Automated layout and point transfer system

ABSTRACT

A two-dimension layout system identifies points and their coordinates, and transfers identified points on a solid surface to other surfaces in a vertical direction. Two leveling laser light transmitters are used with a remote unit to control certain functions. The laser transmitters rotate about the azimuth, and emit vertical (plumb) laser planes. After being set up using benchmark points, the projected lines of the laser planes will intersect on the floor of a jobsite at any point of interest in a virtual floor plan, under control of a user with the remote unit. An “active target” can be used to more automatically create benchmarks. A laser distance meter can be installed on base units to automatically scan a room or a wall to determine certain key features.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of application Ser. No.13/450,769, titled “AUTOMATED LAYOUT AND POINT TRANSFER SYSTEM,” filedon Apr. 19, 2012, which is a continuation-in-part of application Ser.No. 13/287,028, titled “TWO DIMENSION LAYOUT AND POINT TRANSFER SYSTEM,”filed on Nov. 1, 2011, now U.S. Pat. No. 8,281,495, which is acontinuation of application Ser. No. 12/824,716, titled “TWO DIMENSIONLAYOUT AND POINT TRANSFER SYSTEM,” filed on Jun. 28, 2010, now U.S. Pat.No. 8,087,176.

TECHNICAL FIELD

The technology disclosed herein relates generally to layout “surveying”equipment and is particularly directed to a two-dimension layout systemof the type which identifies points and their coordinates, and transfersidentified points on a surface to other surfaces in a verticaldirection. Embodiments are specifically disclosed using two laser lighttransmitters with a remote unit to control certain functions. The lasertransmitters may be identical. Preferably the laser transmitters includea self-leveling capability, and exhibit a rotation about the azimuth,and a vertical (plumb) laser plane (or rotating line) output. When thesystem is set up it is capable of aiming (by rotation) each of thevertical (laser light) plane outputs from the transmitters (which arepositioned at some distance apart), so that the projected lines (of thelaser light planes) will cross on the surface at any given desired pointon the jobsite. In addition, the extent (divergence) of the projectedlaser light planes are such that they also cross overhead on theceiling, which crossing point occurs at a location that is truly plumbabove the corresponding crossing point on the surface. A further featureof the system provides an “implied” plumb line that is projected inspace, and is represented by the intersection of the two planes betweenthe point intersections on the surface and the ceiling. This impliedplumb line is visible if a solid surface (or perhaps smoke) is placed inthe volumetric space where the plumb line is projected. The systemincludes a methodology for simplified layout and direct point transferto the ceiling.

The laser transmitters are mounted on base units that are placed on thefloor surface of a construction jobsite, and vertical laser planes canbe aimed at user-selected points of interest (e.g., corners of anenclosed space or room), and benchmarks can be established at thosepoints of interested on a virtual floor plan. Alternatively, a rod of aknown, fixed length can be placed on the floor surface, and the verticallaser planes emitted by the base units can be aimed at the ends of thatfixed rod, and benchmarks can be established at those positions. Oncethe alignment axis between the base units is known, and the base unitazimuth angles to each rod end are known, and the physical length of therod is entered into a virtual floor plan, then the entire virtual floorplan can be automatically scaled to the true dimensions of the jobsite.

An active target having a wireless transmitter and an omni-directionaloptical sensor can be placed on the same floor surface as the two baseunits of a construction jobsite, and the active target can control themovements of the vertical laser planes emitted by the base units untilthey both intersect at the omni-directional sensor of the active target.The azimuth angle information aiming at the active target, along withthe alignment axis between the base units, can be used to automaticallycreate a benchmark on the jobsite floor. A second active target positioncan then be established to automatically create a second benchmark onthe jobsite floor. The jobsite room can then be scaled for use on avirtual floor plan, and other points of interest can then be located andlaid out.

An enhanced capability base unit is provided with a vertical laser planetransmitter and a laser distance measuring device, both mounted on arotatable platform, and preferably both aiming in the same verticalplane. This equipment allows for even greater automation: a singleenhanced capability base unit can scan a given space of a jobsite todetermine the dimensions of that space, and to establish benchmarks fromuser-selected points of interest, such as corners of a room. A virtualfloor plan can be generated from that information, and a second baseunit can be placed on the same floor surface to establish an alignmentaxis, and then to locate and lay out other points of interest. A singleenhanced capability base unit with a vertical laser plane transmitterand a laser distance measuring device can be used to scan a wall on ajobsite to automatically establish a perpendicular line from the baseunit to that wall (of any length). The user can then easily create aperpendicular chalk line on the jobsite floor, and then can readilycreate multiple parallel chalk lines that will each be perpendicular tothat wall. A pair of enhanced capability base units, each with avertical laser plane transmitter and a laser distance measuring device,can be used to establish benchmarks from user-selected points ofinterest, such as corners of a room on a jobsite. Once two benchmarkshave been established, the entire room dimensions readily can be scaled,and other points of interest then can be located and laid out on a newvirtual floor plan.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

BACKGROUND

The present invention relates generally to a laser system that providesthe elements for visually locating points of interest on atwo-dimensional horizontal surface for use in primarily interiorconstruction environments. A simple, accurate and cost effective systemfor the layout of floor plans at the jobsite has long been in need.Conventional GPS is not usable inside standard steel constructionbuildings. Previous laser based systems have been overly complex andexpensive, missing the mark in almost every area required for thismarket.

In prior art laser based positioning systems, such as disclosed in U.S.Pat. No. 5,100,229, three or more laser transmitters (beacons) areplaced around the perimeter of a work site. Each transmitter emits aplane of light approximately 45 degrees to vertical while continuouslyrotating at a constant speed. The beams from each transmitter must eachhave their own unique and highly controlled speed of rotation, oralternatively their own unique modulation frequency, so they may bedistinguished from each other. A strobe on each provides a referencesignal to start a series of timing events that are ultimately utilizedto triangulate position. The system can be used for two-dimensional orthree-dimensional applications. The complexity of this method is veryhigh, and the requirement of having constant rotational laser scanningis critical. In addition, it is computationally intensive, especiallywhen setting up the system.

Another prior apparatus, such as disclosed in U.S. Pat. No. 5,076,690,uses a rotating laser beam to scan retro-reflective bar coded targetsplaced around the perimeter of the job site. The portabletransmitter/receiver utilizes optical collection optics to receive theretro-reflected energy from at least three of the targets. A rotationalencoder assumes a relatively constant rotation speed and interpolatesbetween each perimeter slot of the encoder disk a precision azimuthangle for each acquired target. After a set-up procedure that uses atleast two known benchmarks, the working field is ‘scaled’ so that anyother point of interest can be found with a two-dimensional workingplane. A complex method to precision calibrate and characterize eachleading edge of each rotary encoder slot is required to provide thelevel of precision sought in the construction layout application. Jobsite obstructions also become a challenge when acquiring sufficienttargets in the right place, with respect to the position of thetransmitter, to provide a strong calculation of position.

Still another method of laser based positioning is disclosed in U.S.Pat. No. 7,110,092. Two parallel laser beams are emitted at a knowndistance from each other. The beams are rotated together at a constantspeed, thus defining the working plane. A laser receiver is used todetermine when each beam becomes incident on the sensing element.Because the rotation of the beams is assumed to be constant, the timingof the two beams incident on the receiver becomes faster at greaterdistances and thus is a smaller percentage of the time it takes totraverse the entire perimeter. Distance is extrapolated from thisinformation. Further, if an index is provided to indicate the start ofrotation of the laser beams, then position can be found. Constantrotation speed is again very critical, and the position calculation forthis method typically has not been sufficient accuracy for what isrequired for typical construction jobsite layout.

Still other laser based methods have been used to provide theconstruction layout function. Several of them, such as thosemanufactured and marketed by SL Laser, Leica, and Flexijet, utilize apointing laser beam that is mounted on a rotating base that can provideazimuth angle and a frame with a rotatable sextant that can providealtitude angle. In this manner a laser beam can be pointed in thedirection of a desired point of interest and projected onto a surface.The indicated point location is accurate only if the surface onto whichit is projected is both flat and at the theoretically expectedelevation. Otherwise serious errors can occur, and become increasinglylarge as the incident projection angle onto the surface becomes steeper.

It is seen that there remains a need for a more effective positioningsystem for use in the construction industry and, more specifically, forfloor layout indoors. This need encompasses the desire for moresimplicity so that its concept of operation and method of use is muchmore intuitive to the user. Set up of the system should bestraightforward and fast. In addition, there is a need to provide avisual system for interior use. Doing so will add to the intuitivenature of the system as well as reduce the overall expense of thesystem, because the function of automatically detecting an encoded ormodulated laser signal is not required. Lastly, there is a need toprovide a system where the projection onto a surface is not subject toflatness errors of the incident surface.

SUMMARY

Accordingly, it is an advantage to provide a floor layout system thatincludes two base units that can have an alignment axis establishedtherebetween, and a remote unit that communicates with both of the baseunits, in which the system is configured to provide a visualpresentation of virtual points on a jobsite physical surface that havepredetermined coordinates, relative to locations of at least twobenchmark points.

It is another advantage to provide a base unit that has a lasertransmitter having an optical emission that creates a vertical laserlight plane, a laser receiver with a null position-detecting capability,in which the receiver is mounted to detect laser light offsets in thehorizontal direction, and a leveling mechanism.

It is yet another advantage to provide a remote unit that has a computerprocessing circuit and a memory circuit, along with a communicationcircuit that can communicate to at least one base unit of a floor layoutsystem, in which the remote unit also has a display and a usercontrolled input device; the remote unit also is in communication with avirtual building plan, and its display is capable of depicting at leasttwo benchmark points and at least one known virtual point that is to bevisually indicated on a jobsite physical surface.

It is still another advantage to provide a method for setting up a floorlayout system, in which the system includes two base units each having alaser transmitter, wherein a user will perform certain functions on ajobsite, including: (a) positioning the two base units on a jobsitefloor, (b) aligning the two laser transmitters of both base units tocreate an alignment axis, (c) locating two benchmark points withintersecting laser light from the two laser transmitters, and (d)determining azimuth angles of the two laser transmitters for thosebenchmark points.

It is a further advantage to provide a method for using a floor layoutsystem having “known” points of a building plan, in which the systemincludes two base units each with a laser transmitter, and including aremote unit that is in communication with the base units; wherein a userperforms certain functions, including: (a) positioning the two lasertransmitters of the base units on a jobsite floor to establish analignment axis therebetween, (b) providing a virtual jobsite floor plan,(c) determining coordinates of two benchmark points of the virtual floorplan and determining azimuth angles of the two laser transmitterscorresponding to those benchmark points, (d) entering coordinates for apoint of interest on the virtual floor plan, and slewing the two lasertransmitters to those coordinates, and (e) visually indicating thephysical point of interest on the jobsite floor, by use the laser lightlines produced by the laser transmitters.

It is yet a further advantage to provide a method for using a floorlayout system to enter “unknown” points of a jobsite into a virtualfloor plan, in which a system has two base units each with a lasertransmitter, and a remote unit that is in communication with the baseunits; wherein a user performs certain functions, including: (a)positioning the two laser transmitters of the base units on a jobsitefloor to establish an alignment axis therebetween, (b) providing avirtual jobsite floor plan, (c) determining coordinates of two benchmarkpoints of the virtual floor plan and determining azimuth angles of thetwo laser transmitters corresponding to those benchmark points, (d)selecting an “unknown” physical point of interest on the jobsite floor,(e) slewing the two laser transmitters so that they create visibleintersecting light lines at that physical point of interest, (f)entering the azimuth angles for the two laser transmitters to determinethe corresponding coordinates of that point of interest on the remoteunit, and (g) using reverse calculations, plotting that physical pointof interest on the virtual floor plan of the remote unit.

It is still another advantage to provide a method for using a floorlayout system to create benchmarks for a virtual floor plan, based oncertain points of interest, in which a system has two base units eachwith a laser transmitter and a remote unit that is in communication withthe base units; wherein the user establishes an alignment axis betweenthe two base units, and then aims both base units at a first point ofinterest, such as a corner, and records the azimuth angle information;the user then aims both base units at a second point of interest andrecords those azimuth angles; the user then measures the actual distancebetween those two points of interest, and scales the data for thevirtual floor plan to be created, thereby establishing the benchmarksfor the physical system.

It is a yet further advantage to provide a method for using a floorlayout system to create benchmarks on a jobsite, using an active targetto establish benchmark positions for a virtual floor plan.

It is still a further advantage to provide an active target apparatuswhich includes an automatic processing circuit with instructions toautomatically communicate to at least one base unit using a wirelesstransmitter, and which includes an omni-directional photosensor with anappropriate gain and demodulation interface to detect laser light thatstrikes the photosensor, and which can send instructions to the baseunits to slew their laser fan beam transmitters back and forth until thefan beams are centered on the omni-directional sensor of the activetarget.

It is another advantage to provide a method for using a floor layoutsystem to establish benchmarks on a jobsite for creating a virtual floorplan, in which two base units each with a laser transmitter are used tocreate an alignment axis, and then to establish the end point positionsof a rod of fixed length that is placed on the floor of a jobsite, andthen to record the azimuth angles to establish the exact angularpositions of the fixed rod, and then to scale the system on a virtualfloor plan into the physical distances of the actual jobsite.

It is still another advantage to provide a base unit that has a lasertransmitter with an optical emission to create a vertical laser lightplane, a laser receiver with a null position-detecting capability, aleveling mechanism, and a distance measuring device that can be aimedalong the same vertical plane as the laser transmitter.

It is a further advantage to provide a method for using a floor layoutsystem on an existing space that has no initial virtual floor plan byplacing a base unit with a laser transmitter that acts as a distancemeasuring device, and to automatically scan the entire space for thedistances to each of the vertical surfaces in that space while recordingthe azimuth angles and distances between the base unit and the targetvertical surfaces, and to then establish benchmarks based on thatinformation.

It is yet a further advantage to provide a method for using a floorlayout system in which the system includes a base unit having a lasertransmitter to create a vertical fan beam, a remote unit that is incommunication with the base unit, and providing a distance measuringdevice on the base unit for establishing a precise distance between thebase unit and a vertical target in the space; wherein a user uses thebase unit to establish multiple distances at corresponding azimuthangles between one of the walls of the space and the base unit, to slewin a horizontal plane the distance measuring device so that it can finda shortest distance to the wall surface, and establish that as theperpendicular line to that wall, thereby squaring up a vertical planefrom the base unit to the wall using the distance measuring device.

It is still a further advantage to provide a method for using a floorlayout system on a jobsite having a space with no initial virtual floorplan, in which the system includes two base units each with a lasertransmitter, and at least one transmitter including a distance measuringdevice, and including a remote unit that is in communication with thebase units; wherein the user establishes an alignment axis between thebase units, and then aims the laser transmitters both at the same pointof interest on the floor surface to establish a first virtual benchmark,by recording the azimuth angles and the actual distance to that virtualpoint, which is simplified if the virtual point is along a vertical wallsurface; this now becomes a benchmark, and the same methodology can beused by aiming at a second point of interest along a second verticalsurface to create a second benchmark; the system can now be scaled tocreate the virtual floor plan.

Additional advantages and other novel features will be set forth in partin the description that follows and in part will become apparent tothose skilled in the art upon examination of the following or may belearned with the practice of the technology disclosed herein.

To achieve the foregoing and other advantages, and in accordance withone aspect, a layout and point transfer system is provided, whichcomprises: (a) a first base unit, having a first laser light transmitterthat emits a first laser light plane, and a first processing circuit;and (b) a second base unit, having a second laser light transmitter thatemits a second laser light plane, and a second processing circuit;wherein: (c) the system is configured to register locations of the firstand second base units on a physical jobsite surface with respect to atleast two previously surveyed benchmark points that are also located onthe physical jobsite surface; and (d) the system is configured toprovide a visual representation of a virtual point on the physicaljobsite surface, by aiming first laser light plane and the second laserlight plane, to indicate a location of the virtual point.

In accordance with another aspect, a base unit for use in a floor layoutand point transfer system is provided, which comprises: a first laserlight transmitter that emits a substantially vertical plane of laserlight, the first laser light transmitter being rotatable about asubstantially vertical axis; a laser light receiver having: anull-position photosensor that is mounted to detect laser light offsetsin a substantially horizontal direction, and an amplifier circuitinterfacing between the null-position photosensor and the laser lightreceiver; and a leveling mechanism.

In accordance with yet another aspect a method for setting up a layoutand point transfer system is provided, in which the method comprises thefollowing steps: (a) providing a first base unit which includes a firstlaser light transmitter that emits a first laser light plane; (b)providing a second base unit which includes a second laser lighttransmitter that emits a second laser light plane; (c) positioning thefirst base unit and the second base unit at two different locations on asolid surface of a jobsite; (d) determining an alignment axis betweenthe first base unit and the second base unit; (e) aiming the first laserlight transmitter and the second laser light transmitter so that a firstbenchmark point is indicated by intersecting laser light lines along thesolid surface, which are produced by the first and second laser lightplanes; and determining a first set of azimuth angles of the first andsecond laser light transmitters; (f) aiming the first laser lighttransmitter and the second laser light transmitter so that a secondbenchmark point is indicated by intersecting laser light lines along thesolid surface, which are produced by the first and second laser lightplanes; and determining a second set of azimuth angles of the first andsecond laser light transmitters; and (g) by use of the first and secondsets of azimuth angles, determining positions of the first and secondbase units with respect to the first and second benchmark points.

In accordance with still another aspect, a base unit for use in a layoutand point transfer system is provided, which comprises: a laser lighttransmitter that emits a substantially vertical plane of laser light,the laser light transmitter being rotatable about a substantiallyvertical axis; a distance measuring device that is rotatable about thesubstantially vertical axis; a laser light receiver having: anull-position photosensor that is mounted to detect laser light offsetsin a substantially horizontal direction, and an amplifier circuitinterfacing between the null-position photosensor and the laser lightreceiver; and a leveling mechanism.

In accordance with a further aspect, a layout and point transfer systemis provided, which comprises: (a) a first base unit, having a rotatablefirst laser light transmitter that emits a first laser light plane, afirst communications circuit, and a first processing circuit; and (b) asecond base unit, having a rotatable second laser light transmitter thatemits a second laser light plane, a second communications circuit, and asecond processing circuit; (c) an active target, having anomni-directional laser light sensor, a third communications circuit, anda third processing circuit; wherein: (d) the active target controlsaiming of the first and second laser light transmitters so that thefirst and second laser light planes both become aimed at theomni-directional laser light sensor, for establishing a position of theactive target as a benchmark for use by the system.

In accordance with a yet further aspect, a method for setting up alayout and point transfer system is provided, in which the methodcomprises the following steps: (a) providing a first base unit whichincludes a first processing circuit, a first communications circuit, afirst azimuth angle measuring instrument, a rotatable first laser lighttransmitter that emits a first laser light plane, and a rotatable firstdistance measuring device that measures distance to a target; (b)providing a second base unit which includes a second processing circuit,a second communications circuit, a second azimuth angle measuringinstrument, and a rotatable second laser light transmitter that emits asecond laser light plane; (c) providing a remote unit that includes athird processing circuit, a third communications circuit, a memorycircuit, a display, and an input sensing device that allows a user toenter commands to the remote unit, the remote unit being incommunication with the first and second base units; (d) positioning thefirst base unit and the second base unit at two different locations on asolid surface of a jobsite; (e) determining an alignment axis betweenthe first base unit and the second base unit; (f) starting a new virtualjobsite floor plan in the memory circuit of the remote unit, for a fieldof work at the jobsite; (g) selecting a first physical point on thesolid surface of the jobsite and aiming the first laser lighttransmitter and the second laser light transmitter so that the firstphysical point is indicated by both laser light lines that are producedby the first and second laser light planes; (h) determining a first setof azimuth angles of the first and second laser light transmitters; (i)determining a first distance between the first physical point and thefirst distance measuring device; (j) recording the first set of azimuthangles and first distance in the memory circuit of the remote unit,thereby creating a first benchmark for the virtual floor plan stored inthe memory circuit; and (k) calculating a second distance between thefirst and second base units, thereby scaling the field of work.

In accordance with still another aspect, a method for setting up alayout and point transfer system is provided, in which the methodcomprises the following steps: (a) providing a first base unit whichincludes a first processing circuit, a first communications circuit, afirst azimuth angle measuring instrument, a rotatable first laser lighttransmitter that emits a first laser light plane, and a rotatable firstdistance measuring device that measures distance to a target; (b)providing a second base unit which includes a second processing circuit,a second communications circuit, a rotatable second laser lighttransmitter that emits a second laser light plane, and a rotatablesecond distance measuring device that measures distance to a target; (c)providing a remote unit that includes a third processing circuit, athird communications circuit, a memory circuit, a display, and an inputsensing device that allows a user to enter commands to the remote unit,the remote unit being in communication with the first and second baseunits; (d) positioning the first base unit and the second base unit attwo different locations on a solid surface of a jobsite; (e) determiningan alignment axis between the first base unit and the second base unit;(f) starting a new virtual jobsite floor plan in the memory circuit ofthe remote unit, for a field of work at the jobsite; (g) selecting afirst physical point on the solid surface of the jobsite and aiming thefirst laser light transmitter and the second laser light transmitter sothat the first physical point is indicated by both laser light linesthat are produced by the first and second laser light planes; (h)determining a first azimuth angle of the first laser light transmitter;(i) determining a first set of distances between the first physicalpoint and the first and second distance measuring devices; (j) recordingthe first azimuth angle and first set of distances in the memory circuitof the remote unit, thereby creating a first benchmark for the virtualfloor plan stored in the memory circuit; and (k) calculating a seconddistance between the first and second base units, thereby scaling thefield of work.

In accordance with a still further aspect, a method for automaticallyfinding a perimeter of a space is provided, in which the methodcomprises the following steps: (a) providing a first base unit whichincludes a first processing circuit, a first communications circuit, afirst azimuth angle measuring instrument, a rotatable first laser lighttransmitter that emits a first laser light plane, and a rotatabledistance measuring device that measures distance to a target; (b)providing a remote unit that includes a second processing circuit, asecond communications circuit, a memory circuit, a display, and an inputsensing device that allows a user to enter commands to the remote unit,the remote unit being in communication with the first base unit; (c)positioning the first base unit at a user-selected location on a solidsurface of a space on a jobsite; (d) scanning the space by rotating thedistance measuring device and recording a plurality of angles anddistances to raised surfaces of the jobsite, for a plurality of angularpositions; and (e) creating a virtual floor plan in the memory circuitof the remote unit, based upon the plurality of recorded angles anddistances.

In accordance with another aspect, a method for determining aperpendicular line up to a wall is provided, in which the methodcomprises the following steps: (a) providing a base unit which includesa processing circuit, an azimuth angle measuring instrument, a rotatablelaser light transmitter that emits a laser light plane, and a rotatabledistance measuring device that measures distance to a target; (b)positioning the base unit at a user-selected location on a solid surfaceof a space on a jobsite; (c) scanning a wall of the space by rotatingthe distance measuring device and recording a plurality of angles anddistances to the wall for a plurality of angular positions; (d)determining two angular positions where a distance to the wall issubstantially equal at both the angular positions; and (e) aiming thelaser light transmitter at an angular direction that bi-sects the twoangular positions, and turning on the laser light transmitter so that itcreates a visible laser light line along the solid surface, therebyindicating a visible perpendicular line to the wall.

In accordance with yet another aspect, a method for setting up a layoutand point transfer system is provided, in which the method comprises thefollowing steps: (a) providing a first base unit which includes a firstprocessing circuit, a first communications circuit, a first azimuthangle measuring instrument, a rotatable first laser light transmitterthat emits a first laser light plane, and a rotatable first distancemeasuring device that measures distance to a target; (b) providing asecond base unit which includes a second processing circuit, a secondcommunications circuit, a second azimuth angle measuring instrument, arotatable second laser light transmitter that emits a second laser lightplane, and a rotatable second distance measuring device that measuresdistance to a target; (c) providing a remote unit that includes a thirdprocessing circuit, a third communications circuit, a memory circuit, adisplay, and an input sensing device that allows a user to entercommands to the remote unit, the remote unit being in communication withthe first and second base units; (d) positioning the first base unit andthe second base unit at two different locations on a solid surface of ajobsite; (e) determining an alignment axis between the first base unitand the second base unit; (f) starting a new virtual jobsite floor planin the memory circuit of the remote unit; (g) selecting a first physicalpoint on at least one raised surface of the jobsite and aiming the firstlaser light transmitter and the second laser light transmitter so thatthe first physical point is indicated by both laser light lines that areproduced by the first and second laser light planes; determining a firstset of azimuth angles of the first and second laser light transmitters;determining a first set of distances between the first physical pointand the first and second distance measuring devices; and recording thefirst set of azimuth angles and first set of distances in the memorycircuit of the remote unit, thereby creating a first benchmark for thevirtual floor plan stored in the memory circuit; and (h) selecting asecond physical point on at least one raised surface of the jobsite andaiming the first laser light transmitter and the second laser lighttransmitter so that the second physical point is indicated by both laserlight lines that are produced by the first and second laser lightplanes; determining a second set of azimuth angles of the first andsecond laser light transmitters; determining a second set of distancesbetween the second physical point and the first and second distancemeasuring devices; and recording the second set of azimuth angles andsecond set of distances in the memory circuit of the remote unit,thereby creating a second benchmark for the virtual floor plan stored inthe memory circuit.

In accordance with still another aspect, a method for setting up alayout and point transfer system is provided, in which the methodcomprises the following steps: (a) providing a first base unit whichincludes a first processing circuit, a first communications circuit, afirst azimuth angle measuring instrument, and a rotatable first laserlight transmitter that emits a first laser light plane; (b) providing asecond base unit which includes a second processing circuit, a secondcommunications circuit, a second azimuth angle measuring instrument, anda rotatable second laser light transmitter that emits a second laserlight plane; (c) providing a remote unit that includes a thirdprocessing circuit, a third communications circuit, a memory circuit, adisplay, and an input sensing device that allows a user to entercommands to the remote unit, the remote unit being in communication withthe first and second base units; (d) providing an active target thatincludes an omni-directional laser light sensor, a fourth communicationscircuit, and a fourth processing circuit; (e) positioning the first baseunit and the second base unit at two different locations on a solidsurface of a jobsite, and positioning the active target at a thirdlocation on the solid surface; (f) determining an alignment axis betweenthe first base unit and the second base unit; (g) starting a new virtualjobsite floor plan in the memory circuit of the remote unit; (h)activating the active target; (i) under control of the active target,aiming the first laser light transmitter and the second laser lighttransmitter so that the omni-directional laser light sensor is impactedby both the first and second laser light planes; determining a first setof azimuth angles of the first and second laser light transmitters; andrecording the first set of azimuth angles in the memory circuit of theremote unit, thereby creating a first benchmark for the virtual floorplan stored in the memory circuit; (j) moving the active target to afourth location on the solid surface; (k) under control of the activetarget, aiming the first laser light transmitter and the second laserlight transmitter so that the omni-directional laser light sensor isimpacted by both the first and second laser light planes; determining asecond set of azimuth angles of the first and second laser lighttransmitters; and recording the second set of azimuth angles in thememory circuit of the remote unit, thereby creating a second benchmarkfor the virtual floor plan stored in the memory circuit; (l) determiningan actual distance between the first benchmark and the second benchmark,and recording the actual distance in the memory circuit of the remoteunit; and (m) scaling the virtual floor plan to actual dimensions of thejobsite, based upon the actual distance between the first and secondbenchmarks.

In accordance with a further aspect, a method for setting up a layoutand point transfer system is provided, in which the method comprises thefollowing steps: (a) providing a first base unit which includes a firstprocessing circuit, a first communications circuit, a first azimuthangle measuring instrument, and a rotatable first laser lighttransmitter that emits a first laser light plane; (b) providing a secondbase unit which includes a second processing circuit, a secondcommunications circuit, a second azimuth angle measuring instrument, anda rotatable second laser light transmitter that emits a second laserlight plane; (c) providing a remote unit that includes a thirdprocessing circuit, a third communications circuit, a memory circuit, adisplay, and an input sensing device that allows a user to entercommands to the remote unit, the remote unit being in communication withthe first and second base units; (d) providing a first active targetthat includes a first omni-directional laser light sensor, a fourthcommunications circuit, and a fourth processing circuit; (e) providing asecond active target that includes a second omni-directional laser lightsensor, a fifth communications circuit, and a fifth processing circuit;(f) positioning the first base unit and the second base unit at twodifferent locations on a solid surface of a jobsite, positioning thefirst active target at a third location on the solid surface, andpositioning the second active target at a fourth location on the solidsurface; (g) determining an alignment axis between the first base unitand the second base unit; (h) starting a new virtual jobsite floor planin the memory circuit of the remote unit; (i) activating the firstactive target; (j) under control of the first active target, aiming thefirst laser light transmitter and the second laser light transmitter sothat the first omni-directional laser light sensor is impacted by boththe first and second laser light planes; determining a first set ofazimuth angles of the first and second laser light transmitters; andrecording the first set of azimuth angles in the memory circuit of theremote unit, thereby creating a first benchmark for the virtual floorplan stored in the memory circuit; (k) deactivating the first activetarget; (l) activating the second active target; (m) under control ofthe second active target, aiming the first laser light transmitter andthe second laser light transmitter so that the second omni-directionallaser light sensor is impacted by both the first and second laser lightplanes; determining a second set of azimuth angles of the first andsecond laser light transmitters; and recording the second set of azimuthangles in the memory circuit of the remote unit, thereby creating asecond benchmark for the virtual floor plan stored in the memorycircuit; (n) determining an actual distance between the first benchmarkand the second benchmark, and recording the actual distance in thememory circuit of the remote unit; and (o) scaling the virtual floorplan to actual dimensions of the jobsite, based upon the actual distancebetween the first and second benchmarks.

In accordance with a yet further aspect, a method for setting up alayout and point transfer system is provided, in which the methodcomprises the following steps: (a) providing a first base unit whichincludes a first processing circuit, a first communications circuit, afirst azimuth angle measuring instrument, and a rotatable first laserlight transmitter that emits a first laser light plane; (b) providing asecond base unit which includes a second processing circuit, a secondcommunications circuit, a second azimuth angle measuring instrument, anda rotatable second laser light transmitter that emits a second laserlight plane; (c) providing a remote unit that includes a thirdprocessing circuit, a third communications circuit, a memory circuit, adisplay, and an input sensing device that allows a user to entercommands to the remote unit, the remote unit being in communication withthe first and second base units; (d) providing a fixed-length rod, therod having a first indicia proximal to a first end and a second indiciaproximal to a second, opposite end along a longitudinal axis, the rodhaving a known actual length between the first and second indicia; (e)positioning the first base unit and the second base unit at twodifferent locations on a solid surface of a jobsite, and positioning thefixed-length rod at a third location on the solid surface; (f)determining an alignment axis between the first base unit and the secondbase unit; (g) starting a new virtual jobsite floor plan in the memorycircuit of the remote unit; (h) aiming the first laser light transmitterand the second laser light transmitter so that the first indicia of therod is indicated by intersecting laser light lines that are produced bythe first and second laser light planes; determining a first set ofazimuth angles of the first and second laser light transmitters; andrecording the first set of azimuth angles in the memory circuit of theremote unit, and thereby creating a first benchmark for the virtualfloor plan stored in the memory circuit; (i) aiming the first laserlight transmitter and the second laser light transmitter so that thesecond indicia of the rod is indicated by intersecting laser light linesthat are produced by the first and second laser light planes;determining a second set of azimuth angles of the first and second laserlight transmitters; and recording the second set of azimuth angles inthe memory circuit of the remote unit, and thereby creating a secondbenchmark for the virtual floor plan stored in the memory circuit; and(j) scaling the virtual floor plan to the known actual length, whichrepresents the physical distance between the first and secondbenchmarks.

Still other advantages will become apparent to those skilled in this artfrom the following description and drawings wherein there is describedand shown a preferred embodiment in one of the best modes contemplatedfor carrying out the technology. As will be realized, the technologydisclosed herein is capable of other different embodiments, and itsseveral details are capable of modification in various, obvious aspectsall without departing from its principles. Accordingly, the drawings anddescriptions will be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the technology disclosedherein, and together with the description and claims serve to explainthe principles of the technology. In the drawings:

FIG. 1 is a block diagram of the major components of a layout and pointtransfer system, as constructed according the principles of thetechnology disclosed herein.

FIG. 2 is a block diagram of the major components of a laser transmitterthat is part of a base unit depicted in FIG. 1.

FIG. 3 is a block diagram of the major components of a laser receiverthat is part of a base unit that is depicted in FIG. 1.

FIG. 4 is a block diagram of the major components of a remote unit thatis part of the system of FIG. 1.

FIG. 5 is a flow chart of the steps performed by a system set-uproutine, for the system depicted in FIG. 1.

FIG. 6 is a flow chart of the steps performed by a routine to find a“known” point on a floor layout plan, using the system of FIG. 1.

FIG. 7 is a flow chart of the steps performed by a routine to enter an“unknown” point on a jobsite, using the system of FIG. 1.

FIG. 8 is a diagrammatic view of an “automatic” base unit, as used inthe system of FIG. 1.

FIGS. 9-13 are diagrammatic views of how a human user would use thesystem of FIG. 1, first to align a pair of transmitter axes, then toalign the transmitters to two different benchmark points, then to alignthe laser planes to a floor point, and finally to align the laser planesalong a plumb line of a wall surface.

FIGS. 14-19 are diagrammatic views showing how two base units of thesystem of FIG. 1 can automatically establish an alignment axistherebetween.

FIG. 20 is an elevational view of a conventional laser position pointingsystem that is known in the prior art, depicting its attempt to projecta position of a point of interest on an uneven jobsite floor.

FIG. 21 is an elevational view of the system of FIG. 1, showing two baseunits with laser transmitters that correctly project a position of apoint of interest on an uneven jobsite floor.

FIG. 22 is a diagram showing positions of physical points and anglesinvolved in a set-up routine.

FIG. 23 is a diagram showing positions of physical points and anglesinvolved in a routine for locating a known point of interest.

FIG. 24 is a diagram showing positions of physical points and anglesinvolved in a routine for entering an unknown point of interest.

FIG. 25 is a block diagram of the major components of a base unit withenhanced capabilities that is used in a layout and point transfersystem, as constructed according to the principles of the technologydisclosed herein.

FIG. 26 is a block diagram of the major components of a laser receiverwith enhanced capabilities that is part of the base unit that isdepicted in FIG. 25.

FIG. 27 is a diagrammatic view of an enhanced capabilities “automatic”base unit, as used in the system of FIG. 25.

FIGS. 28-32 are diagrammatic views showing how two base units of thetype described herein can automatically establish an alignment axistherebetween, from the perspective of a human user in an existing space.

FIGS. 33-35 are diagrammatic views showing how two base units of thesystem in FIG. 28 can be used to align the transmitters of the baseunits to two different benchmark points.

FIGS. 36-37 are diagrammatic views showing how two base units of thesystem of FIG. 28 can be used for setting up a jobsite in a space byusing a pair of aligned base units, but with no known benchmarkspreviously established.

FIG. 38 is a diagrammatic view showing how an enhanced capabilities baseunit of the type of FIG. 27 can be used to scan a room of an existingspace and find the perimeter with a laser distance meter, and ultimatelyestablish benchmark points for a virtual floor plan.

FIGS. 39-40 are diagrammatic views showing how an enhanced capabilitiesbase unit of FIG. 27 can be used to square a vertical plane up to a wallusing a laser distance meter.

FIG. 41 is a diagrammatic view showing how two enhanced capabilitiesbase units of FIG. 27 can be used to create a single vertical line on awall, then taking a distance measurement from each base unit with alaser distance meter mounting thereto, and then establishing benchmarkpoints to create a virtual floor plan.

FIG. 42 is a block diagram of the major components of an active targetthat can be used with the base units of FIG. 2.

FIGS. 43-47 are diagrammatic views showing how two base units and anactive target can be used to create benchmarks in an existing space, andthereafter to create a virtual floor plan.

FIGS. 48-50 are diagrammatic views showing how two base units can beused with a rod of fixed length to establish benchmarks on the floor ofan existing space, and then to create a virtual floor plan from thatinformation.

FIG. 51 is a flow chart of the steps performed by a routine to createbenchmarks for an existing room, and then create a virtual floor layoutplan, using the system of FIG. 1.

FIG. 52 is a flow chart of the steps performed by a routine to scan anexisting room to find its perimeter, and then create a virtual floorlayout plan, using the system of FIG. 25.

FIG. 53 is a flow chart of the steps performed by a routine to square avertical plane up to a wall of an existing room, using the base unit ofFIG. 26.

FIG. 54 is a flow chart of the steps performed by a routine to createbenchmarks for an existing room, and then create a virtual floor layoutplan, using the system of FIG. 25.

FIG. 55 is a flow chart of the steps performed by a routine to createbenchmarks for an existing room, and then create a virtual floor layoutplan, using an active target and portions of the system of FIG. 1.

FIG. 56 is a flow chart of the steps performed by a routine to createbenchmarks for an existing room, and then create a virtual floor layoutplan, using a rod of known fixed length and portions of the system ofFIG. 1.

DETAILED DESCRIPTION

Reference will now be made in detail to the present preferredembodiment, an example of which is illustrated in the accompanyingdrawings, wherein like numerals indicate the same elements throughoutthe views.

It is to be understood that the technology disclosed herein is notlimited in its application to the details of construction and thearrangement of components set forth in the following description orillustrated in the drawings. The technology disclosed herein is capableof other embodiments and of being practiced or of being carried out invarious ways. Also, it is to be understood that the phraseology andterminology used herein is for the purpose of description and should notbe regarded as limiting. The use of “including,” “comprising,” or“having” and variations thereof herein is meant to encompass the itemslisted thereafter and equivalents thereof as well as additional items.Unless limited otherwise, the terms “connected,” “coupled,” and“mounted,” and variations thereof herein are used broadly and encompassdirect and indirect connections, couplings, and mountings. In addition,the terms “connected” and “coupled” and variations thereof are notrestricted to physical or mechanical connections or couplings.

In addition, it should be understood that embodiments disclosed hereininclude both hardware and electronic components or modules that, forpurposes of discussion, may be illustrated and described as if themajority of the components were implemented solely in hardware.

However, one of ordinary skill in the art, and based on a reading ofthis detailed description, would recognize that, in at least oneembodiment, the electronic based aspects of the technology disclosedherein may be implemented in software. As such, it should be noted thata plurality of hardware and software-based devices, as well as aplurality of different structural components may be utilized toimplement the technology disclosed herein.

It will be understood that the term “circuit” as used herein canrepresent an actual electronic circuit, such as an integrated circuitchip (or a portion thereof), or it can represent a function that isperformed by a processing device, such as a microprocessor or an ASICthat includes a logic state machine or another form of processingelement (including a sequential processing device). A specific type ofcircuit could be an analog circuit or a digital circuit of some type,although such a circuit possibly could be implemented in software by alogic state machine or a sequential processor. In other words, if aprocessing circuit is used to perform a desired function used in thetechnology disclosed herein (such as a demodulation function), thenthere might not be a specific “circuit” that could be called a“demodulation circuit;” however, there would be a demodulation“function” that is performed by the software. All of these possibilitiesare contemplated by the inventors, and are within the principles of thetechnology when discussing a “circuit.”

System Set-Up; Introduction

It is assumed that there exists at least two known points (alsosometimes referred to as “benchmarks” herein) on the jobsite which canbe utilized for the setting up the system. These benchmark points wouldhave been established from previous survey efforts. FIGS. 9-11illustrate a basic example of how the system can be set up. A first step(see FIG. 9) illustrates an alignment of the transmitters' outputvertical planes to each other with the use of an RF (radio frequency)remote unit. This establishes an axis between the centerlines of eachtransmitter “base unit” device and indexes the angular encoders to that.This process can be performed by visually aligning the transmitterplanes to each other, but may be facilitated with the addition of asplit photocell or omni-directional sensor on the transmitter base unitsthat would guide and lock into place the respective planes, addingconvenience and precision to the process.

A second step (see FIG. 10) illustrates the establishment of the firstknown benchmark. The vertical planes from each transmitter base unit arecommanded to position over the point of interest by the handheld radioremote unit, and then their coordinates are entered. The second knownbenchmark is entered in a similar manner, in a third step (asillustrated in FIG. 11). After this third step, the remote unit'scomputer system has sufficient set-up information to calculate thelocation and “find” any other point of interest within the working area.The above example steps will be discussed below, in greater detail.

Finding a “Known” Point; Introduction

FIG. 12 illustrates a basic configuration of laser transmitters andoutput laser plane configurations for a system that was previouslyset-up. The vertical laser light planes emitted by the base unit lasertransmitters can be visible red laser light; however, other lightwavelengths could be used instead, such as infrared, green, or otherlight wavelengths as well. For many of the applications using thissystem, it will be preferable for the laser light to be of a visiblewavelength, and the description hereinbelow will assume that is thecase.

The laser planes emanate from the two laser transmitters' rotors, whichhave capability of rotation about the vertical instrument axis. Thisallows each laser transmitter the ability to position its visiblevertical plane at any angle about its rotation axis, and then to holdstatic at that position. The laser transmitters are located at adistance (not necessarily known) from each other; in this example, theyare positioned near each corner of the room. As can be seen from FIG.12, a first point is formed on the floor at the intersection of the twolaser planes. In addition, a second point is formed on the ceiling,above the first point on the floor. If the two laser planes are trulyvertical with respect to gravity, then the point on the ceiling is in alocation that is plumbed over the point on the floor. Anotherinteresting aspect is the formation of an implied plumb line where thetwo laser planes intersect.

When the system is set up on a jobsite, the laser planes can becommanded to rotate into position so that the intersection identifiesany point of interest (on the floor or ceiling) that the user chooses.This is accomplished via the remote unit (using, for example, a radiolink or an IR link) that communicates with the two base unit lasertransmitters, thereby allowing the user mobility throughout the room andenabling him/her to be at the physical location where the layout work isbeing performed.

Once the set-up is completed the user may enter coordinates of interestinto the handheld remote unit. When this occurs each vertical laserplane can be commanded to slew into position so that the visibleintersection will reveal the physical location. Points of interest mayalso be downloaded from other support software so that the user cansimply choose various points of interest from a listing. Floor layoutcan proceed accordingly. Because there exists a “second” intersection onthe ceiling that is continuously plumbed over the “first” intersectionon the floor, point transfer from floor to ceiling can proceedsimultaneously. This is of use in laying out sprinkler systems and thelike. In addition, there is a vertical implied plumb line at theintersection of the two vertical planes (i.e., between the two floor andceiling intersection points). This vertical implied plumb line can beused to help align and set studded walls—an example of this methodologyis illustrated in FIG. 13. These examples will be discussed below, ingreater detail.

Details of System Hardware

Referring now to FIG. 1, an entire layout and point transfer system,generally designated by the reference numeral 10, is depicted in blockdiagram form. A first base unit is generally designated by the referencenumeral 20, and is also referred to on FIG. 1 as “BASE UNIT #A.” Asecond base unit is generally designated by the reference numeral 30,and is also referred to on FIG. 1 as “BASE UNIT #B.”

Base unit 20 includes a laser transmitter “T1,” at reference numeral 22.Laser transmitter 22 includes a processing circuit, a memory circuit, aninput/output circuit, a laser light source, and a leveling platform.

Base unit 20 contains a laser receiver “R1,” in a preferred mode of thissystem. This laser receiver is also designated by the reference numeral24, and includes a processing circuit, a memory circuit, an input/outputcircuit, and at least one photosensor. Different configurations ofphotosensors can be used for this laser receiver, as discussed below ingreater detail.

Base unit 20 further includes an aiming platform “A1,” which isdesignated by the reference numeral 26. This aiming platform includes anangle encoder, and an angle drive circuit. This aiming platform 26 willbe described in greater detail below.

Base unit 30 includes a laser transmitter, in this instance referred toas “T2,” and designated by the reference numeral 32. Laser transmitter32 also includes a processing circuit, memory circuit, input/outputcircuit, laser light source, and a leveling platform.

Base unit 30 also includes a laser receiver referred to as “R2,” andgenerally designated by the reference numeral 34. This laser receiveralso includes a processing circuit, memory circuit, input/out circuit,and photosensors.

Base unit 30 also includes an aiming platform, referred to as “A2,” andgenerally designated by the reference numeral 36. This second aimingplatform includes an angle encoder, and an angle drive circuit. Theseare similar to the same types of devices in the aiming platform 26, andwill be discussed below in greater detail.

The system 10 also includes a remote unit, which is generally designatedby the reference numeral 40 on FIG. 1. Remote unit 40 includes aprocessing circuit, a memory circuit, an input/out circuit, a display,and a keypad. Alternatively, remote unit 40 could include a touch screendisplay which would incorporate the main functions of a keypad, withouthaving a separate keypad on the unit. The memory circuit of remote unit40 can have two components: a first internal component, and either anexternal component or a “bulk memory” component, which is designated bythe reference numeral 42 on FIG. 1. The external characteristic ofmemory circuit 42 could be comprised of a flash memory or other type ofportable memory device, such as a “stick ROM.” Such a portable memorydevice could be carried by a user, and could be plugged into a port ofthe remote unit 40, if desired. This will be discussed in greater detailbelow.

Another possible component of system 10 is a computer generallydesignated by the reference numeral 50. This computer is referred to asan “ARCHITECT COMPUTER,” on FIG. 1. Although the owner of computer 50may or may not truly be an architect, for the purposes of thisdescription, it will be assumed that computer 50 includes floor plans orsome other type of computer files that were either created or used by anarchitect, or by some type of building engineer. This assumes that thesystem 10 is going to be used on a jobsite in which a building will beconstructed. Of course, other types of outdoor structures or perhapshighways can use the technology disclosed herein, and such a jobsite maynot have any type of enclosed building structure at all. In other words,many of the principles of the technology disclosed herein will also workwell on jobsites that are entirely outdoors.

The computer 50 includes a processing circuit, a memory circuit, and aninput/output circuit. The memory circuit of computer 50 will eithercontain floor plans (designated at 54), or some other type of computerfiles such as computer-aided drafting (CAD) files at 52, on FIG. 1. Itshould be noted that the remote unit 40 itself could have some type ofcomputer-aided architecture or CAD software installed thereon (dependingon how “powerful” the computer/memory system is for the remote unit),and in that event, the virtual floor plan could also be directlycontained in memory circuit 42, and displayed in two, or perhaps eventhree dimensions.

It will be understood that all of the main units illustrated on FIG. 1include some type of input/output circuit, and these types of circuitsinclude communications circuits. Such communication circuits possiblycould be plug-in ports, such as USB ports; moreover, such input/outputcircuits also can include wireless communications circuits, such as lowpower radio-frequency transmitters and receivers, or other types ofwireless communications ports that use other wavelengths, such asinfrared light, for transmitting and receiving data between the variousunits. This type of technology is already available today, althoughcertainly there will be newer forms invented in the future, that canstill be used in the system 10 of FIG. 1.

Referring now to FIG. 2, a block diagram of a laser transmitter used inone of the base units is illustrated, and is generally designated by thereference numeral 100. Laser transmitter 100 includes a processingcircuit 110, which will have associated random access memory (RAM) at112, associated read only memory (ROM) at 114, and at least oneinput/output circuit at 116. These devices 112, 114, and 116 communicatewith the processing circuit 110 by use of a bus 118, which typically isreferred to as an address bus or a data bus, and can also contain othertypes of signals, such as interrupts and perhaps other types of timingsignals.

The input/output circuit 116 will sometimes also be referred to hereinas an I/O circuit. This I/O circuit 116 is a primary interface betweenthe real world devices and the processing circuit 110. It is incommunication with various communications devices and also various typesof motor drive circuits and sensor circuits.

The input/output circuit 116 is in communication with a communicationsport A, which is generally designated by the reference numeral 120.Communications port 120 includes a transmitter circuit 122 and receivercircuit 124. Communications port 120 is provided to exchange datainformation with the remote unit 40, which on FIG. 2 is referred to asthe remote unit 300. The communication link between remote unit 300 andcommunications port 120 is designated by the reference numeral 126. In apreferred mode of this system, the communication link 126 will bewireless, although certainly a cable could be connected between thecommunications port 120 and the remote unit 300, if desired.

A second communications port, referred to as port B is generallydesignated by the reference numeral 130 on FIG. 2. This port 130comprises a data interface with an input circuit at 132 and outputcircuit at 134. Communications port 130 transfers data to and from anull-position photosensor, generally designated by the reference numeral200, using a communication path 136. While it would be possible forcommunication link 136 to be wireless, there is no particular need forthat to be so. The null-position photosensor 200 will typically bemounted directly on the base unit, as will be the laser transmitter 100.Therefore, a direct “wired” link will be typical.

Laser transmitter 100 also includes a leveling motor drive circuit,generally designated by the reference numeral 140. This drive circuitprovides the voltage and current for a leveling motor 142. In addition,it receives signals from a level sensor 144, and these input signalswill determine what types of commands will be sent to the motor 142 fromthe drive circuit 140. If desired, this can be a self-contained systemthat may not need to communicate with the processing circuit 110.However, the laser transmitter 100 will typically desire knowledge ofwhether or not the base unit has actually finished its leveling functionbefore the laser transmitter 100 begins to function in its normal modeof operation. In addition, the processing circuit 110 may well desire tocontrol the leveling motor drive circuit 140, essentially to keep itde-energized at times when it is not critical for the base unit toactually be attempting to level itself with respect to gravity.

Laser transmitter 100 also includes an angle encoder 150, in a preferredembodiment. Angle encoder 150 will provide input signals to theprocessing circuit 110, so that it knows exactly where the lasertransmitter is being pointed with respect to the azimuth direction. Thiscould be a wholly manual operation, if desired to reduce system cost byeliminating the encoder. However, for a fully automated system, theangle encoder 150 will be necessary.

Laser transmitter 100 preferable will also include an azimuth motordrive, generally designated by the reference numeral 160. Motor drive160 will provide the proper current and voltage to drive the azimuthmotor 162, which is the motive force to aim the laser transmitter. Thisagain could be part of a self-contained system, working with the angleencoder 150; however, on FIG. 2, it is illustrated as being controlledby the processing circuit 110.

Laser transmitter 100 also includes a laser light source driver circuit170, which provides the current and voltage to drive a laser lightsource 172. This typically will be a laser diode, although it could bean other type of laser light beam emitter, if desired. As describedabove, the laser light source will typically be emitting visible light,although a non-visible light source could be desirable for certainapplications, and a laser light source emitting infrared light could beused in that situation. The laser source driver 170 is controlled byprocessing circuit 110 in the configuration illustrated on FIG. 2.

The laser transmitter 100 will typically be a “fan beam” lasertransmitter for use in the system 10. However, it will be understoodthat other types of laser light sources could be used, including arotating laser beam (such as a dithering laser beam), if desired. Theremust be some minimum amount of divergence to create a laser light“plane” so that the laser light will at least intersect the floorsurface of a jobsite, and preferably also intersect a ceiling surfacefor spaces on jobsites. The system 10 will have many uses, even if thelaser light source only is pointing at a floor surface, but system 10expands its usefulness if the divergence angle of the laser plane isdesigned to intersect not only the floor, but also the ceiling of thespace. In this description, it will be assumed that the laser lightsource is a fan beam laser or an equivalent, so that either (i) acontinuous plane of laser light is being emitted by each lasertransmitter 100 at both base units 20 and 30, or (ii) a moving beam oflaser light (i.e., a stream of photons in a line that moves its aimingangle over time) is emitted by both base units 20 and 30 in a manner soas to create two “planes” of laser light that each emulates a fan beam.

Referring now to FIG. 3, a laser receiver generally designated by thereference numeral 200 is depicted in block diagram form. Laser receiver200 includes a processing circuit 210, which has associated RAM 212, ROM214, and an input/output interface circuit 216. These devicescommunication with the processing circuit 210 over a bus 218, typicallyincluding at least data and address lines.

The input/output circuit 216 receives signals from some type ofphotosensor. On FIG. 3 two different types of photosensors are depicted.A “butt end” photosensor is depicted at the reference numeral 220, andthis assumes there are only two individual photocells. Each of thesephotocells of the photosensor 220 provides an electrical signal to again stage 222. The output of the gain stage is directed to ademodulation circuit 224, and the output of that circuit directs asignal to the I/O circuit 216. It will be understood that a demodulationcircuit will not be necessary unless the laser light signals themselvesare of a modulated type of signal. In most applications for the system10, a modulated laser light signal will be desirable, and thus ademodulation circuit 224 will be used in those instances.

The second type of photosensor is depicted as a portion of what issometimes referred to as a “rod sensor” and is designated by thereference numeral 230. An exemplary “full” rod sensor is disclosed inU.S. Pat. No. 7,110,092, which issued on Sep. 19, 2006, which disclosureis incorporated by reference herein in its entirety. It will beunderstood that the second photosensor 230 can comprise virtually anytype of “all-around” light-sensing device, i.e., a photosensor that isable to detect incoming light from essentially any angle.

A typical “full” rod sensor would have two photocells, one at each endof the light-conducting rod. However, rod sensor 230 has only a singlephotocell in FIG. 3, which produces an electrical signal that isdirected to a gain stage 232, which outputs a signal to a demodulationstage 234. As in the other type of photosensor circuit described above,the demodulation circuit 234 is only necessary if the laser light sourceemits a modulated signal, which would be typical for this system 10.

An interface circuit 240 is also provided in the laser receiver 200.This is a separate interface circuit from the I/O circuit 216. Interfacecircuit 240 communicates position information to the laser transmittercommunications port B, which will be used in helping “aim” the lasertransmitters during a portion of the set-up mode of operation, asdiscussed below.

Referring now to FIG. 4, a block diagram is provided for a remote unit,which is generally designated by the reference numeral 300. Remote unit300 includes a processing circuit 310, with associated RAM 312, ROM 314,some type of bulk memory or external memory 316, and an input/outputcircuit 318. These circuits are all in communication with the processingcircuit 310 via a bus 315, which normally would carry data signals andaddress signals, and other types of microprocessor signals, such asinterrupts.

The bulk memory 316 could be a disk drive, or perhaps some type of flashmemory. If in the form of flash memory, it could be an external memorydevice (such as a “portable memory device”) that can plug into theremote unit, via a USB port, for example. In that situation, there wouldbe a USB interface between the bulk memory device 316 and the bus 315.

The I/O circuit 318 will be in communication with a first communicationsport 320, which is designated as communications port “X” on FIG. 4.Communications port 320 includes a transmitter circuit 322, and areceiver circuit 324. Communications port 320 is designed to communicatewith the base units 20 and 30, typically using a wireless signal via awireless pathway 326 (as noted on FIG. 4). As described in greaterdetail below, the base units 20 and 30 will communicate azimuth angularinformation with the remote unit, and that information arrives via thewireless path 326 to and from communications port 320.

A second communications port 330 is included in remote unit 300, andthis is designated as communications port “Y” on FIG. 4. Communicationsport 330 includes a transmitter circuit 322 and receiver circuit 334.This communications port 330 is provided to exchange information withthe architect computer 50, via a communication link 336. On FIG. 4,communication link 336 is depicted as a wireless link, although itcertainly could be constructed by use of an electrical cable or anoptical cable, if desired. Communications port 330 will exchange floorlayout data with the architect computer 50; more specifically, it canreceive a floor plan and store it in the bulk memory circuit 316. Inaddition, if the remote unit 300 receives information about a new or“unknown” point of interest in the physical jobsite floor plan, thenthat information can not only be saved in the bulk memory circuit 316,but could be also communicated back to the architect computer 50, viathe communications port 330 to be placed in the original floor plan. Or,a revised floor plan (which includes the new point of interest) can besaved as a file in bulk memory circuit 316, and that entire file couldbe transferred to the architect computer 50.

It will be understood that the architect computer 50 could comprise a“fixed” unit that essentially remains in the architect's office, andpasses data to the remote unit 300 while the remote unit is physicallyat the office, or perhaps they remotely communicate with one another viaa wide area network, such as the Internet. Alternatively, the architectcomputer 50 could comprise a “portable” unit that is transported to thejobsite, and communicates with portable unit 300 while on site. Finally,as portable computers become even smaller in physical size, it is morelikely that the portable unit and the architect computer will eventuallybecome merged into a single device.

A display driver circuit 340 is in communication with the I/O circuit318. Display driver circuit 340 provides the correct interface and datasignals for a display 342 that is part of remote unit 300. If remoteunit 300 is a laptop computer, for example, then this would be thestandard display seen in most laptop computers. Or, perhaps the remoteunit 300 is a calculator-sized computing device, such as a PDA (PersonalDigital Assistant), in which case the display would be a much smallerphysical device. Display 342 could be a touch screen display, ifdesired.

One example of a type of remote unit that could work in this system(with some modification) is the portable “layout manager,” which is anexisting hand held computer sold by Trimble Navigation Limited, ModelNumber LM80. It should be noted that one cannot simply take the LM80 andimmediately use it as a remote unit in the present system; the softwaremust be modified to perform the necessary calculations, which aredescribed below. In addition, the input/output circuits must be modifiedto be able to communicate commands and data both to and from the baseunits.

A keypad driver circuit 350 is in communication with I/O circuit 318.Keypad driver circuit 350 controls the signals that interface to aninput sensing device 352, such as a keypad, as depicted on FIG. 4.Again, if the display 342 is of a touch screen type, then there may notbe a separate keypad on remote unit 300, because most of the command ordata input functions will be available by touching the display itself.There may be some type of power on/off switch, but that would notnecessarily be considered a true keypad (and typically would not be usedfor entering data).

Details of System Methodology

Referring now to FIG. 5, a flow chart is provided for a routine thatperforms a system set-up function. Beginning with an initialization step400, the user positions two base units, and then places both base unitsinto their set-up mode of operation, at a step 402 on FIG. 5. Beginningat a step 410, the two base units are aligned using a predeterminedroutine. An example of how this alignment occurs is provided below, andalso is illustrated beginning at FIG. 14.

At a step 412, the alignment routine begins by aiming the laser beam ofbase unit “A” at a target that is located on base unit “B.” A similarsituation occurs at the opposite laser transmitter; at a step 414 thelaser beam of base unit “B” is aimed at a target on the base unit “A.”(See a more detailed description below, in connection with FIGS. 14-19.)

At a step 416, the angular aim of both base units is adjusted untiltheir laser beams create an alignment axis. If a manual or visualalignment is going to be used, then the logic flow travels to a step418. Alternatively, an automatic alignment occurs if there are laserreceivers mounted to the base units; in that situation the logic flow isdirected to a step 420.

Once an alignment axis is created, a step 422 allows the operator toenter data from the angular encoders to the remote unit. (Note that thesystem software can be programmed to do this automatically.) The userwould typically be handling the remote unit itself (i.e., remote unit420), and by entering a command on its keypad or touch screen, theremote unit 40 will request the alignment information from both baseunits, and then store that angular encoder information into the memorycircuit 316 of remote unit 300. Once this has occurred, the two lasertransmitters of base units “A” and “B” are situated in a fixedrelationship with respect to one another, and are ready for a floorlayout session. The logic flow now arrives at a step 430, which begins aroutine that establishes the benchmarks.

To establish benchmarks, a step 432 requires the user to visually locatetwo benchmark points on the floor surface at the jobsite. At a step 434,the user selects a first benchmark point, designated “B1.” The user nowaims both laser beams for base unit A and base unit B at this point B1.This will be very easy to do, because the laser beams are actuallyvertical laser planes, and if the light emanating from the lasertransmitters comprises visible light, then there will be a thin line ofvisible light crossing the floor surface from each of the base units Aand B. After both laser beams are aimed directly at the first benchmarkpoint B1, then there will be an intersection of the two laser beamsexactly at benchmark point B1. Once that occurs, the user can enter theaiming data for point B1 into the remote unit at a step 436. Thisestablishes the angular relationship between the two base units A and Band the first benchmark point B1.

The user now selects a second benchmark point “B2,” at a step 440. Bothlaser beams from both base units are now aimed at point B2, in a similarfashion to that described above for benchmark point B1, at step 434.After both laser beams are correctly pointed, there will be a visibleline intersection exactly at benchmark point B2, and the user willeasily see this if the laser beams are emanating visible light. Oncethat has occurred, the user can enter the point B2 aiming data into theremote unit, at a step 442.

Once the remote unit has both sets of aiming data for both benchmarkpoints B1 and B2, then a step 450 allows the remote unit to calculatethe distance between base units A and B on the virtual floor plan thatis contained in the memory circuit 316 of the remote unit 300, usingthese base unit positions. These calculations can use a set of exampleequations that are provided hereinbelow:

The following are general case calculations for setting up the system.It is expected that the two transmitters will be placed in someconvenient locations for the job site. The axis between the twotransmitters will be established by aligning the fan beams relative toeach other. It will be desired to calculate the distance between the twotransmitters. See, FIG. 22 for a diagram that illustrates therelationship of physical points and angles involved in the set-uproutine.

Definitions

-   -   T1 Transmitter 1    -   T2 Transmitter 2    -   B1 Benchmark 1 (Known point—previously established)    -   B2 Benchmark 2 (Known point—previously established)    -   A1 Axis between the two transmitters

Knowns:

-   -   D Distance between Benchmark 1 and Benchmark 2    -   A1 The axis between the two transmitters.    -   α Angle transmitter 1 measures from the axis A1 to Benchmark 2    -   γ Angle transmitter 2 measures from the axis A1 to Benchmark 1    -   β Angle Transmitter 1 measures between Benchmark 1 and Benchmark        2    -   δ Angle Transmitter 2 measures between Benchmark 1 and Benchmark        2

It is desired to find the distance ‘d’ between the transmitters T1 andT2:

$\begin{matrix}{{\frac{d}{\sin\left( {\pi - \alpha - \beta - \gamma} \right)} = \frac{a}{\sin(\gamma)}}{{\tan(\gamma)} = \frac{a \cdot {\sin\left( {\alpha + \beta} \right)}}{r}}} & {{Eq}.\mspace{14mu} 1} \\{r = \frac{a \cdot {\sin\left( {\alpha + \beta} \right)}}{\tan(\gamma)}} & {{Eq}.\mspace{14mu} 3} \\{{\frac{d}{\sin\left( {\pi - \alpha - \beta - \delta} \right)} = \frac{b}{\sin(\alpha)}}{{\tan(\alpha)} = \frac{b \cdot {\sin\left( {\gamma + \delta} \right)}}{s}}} & {{Eq}.\mspace{14mu} 2} \\{s = \frac{b \cdot {\sin\left( {\gamma + \delta} \right)}}{\tan(\alpha)}} & {{Eq}.\mspace{14mu} 4} \\{{\sin(\rho)} = \frac{{b \cdot {\sin\left( {\gamma + \delta} \right)}} - {a \cdot {\sin\left( {\alpha + \beta} \right)}}}{D}} & {{Eq}.\mspace{14mu} 5} \\{{r + s - d} = {D \cdot {\cos(\rho)}}} & {{Eq}.\mspace{14mu} 6}\end{matrix}$

From Eq. 1:

$a = \frac{d \cdot {\sin(\gamma)}}{\sin\left( {\pi - \alpha - \beta - \delta} \right)}$

Substitute Eq. 1 into Eq. 3:

$\begin{matrix}{r = \frac{d \cdot {\sin(\gamma)} \cdot {\sin\left( {\alpha + \beta} \right)}}{{\sin\left( {\pi - \alpha - \beta - \gamma} \right)} \cdot {\tan(\gamma)}}} & {{Eq}.\mspace{14mu} 7}\end{matrix}$

From Eq. 2:

$b = \frac{d \cdot {\sin(\alpha)}}{\sin\left( {\pi - \alpha - \gamma - \delta} \right)}$

Substitute Eq. 2 into Eq. 4:

$\begin{matrix}{s = \frac{d \cdot {\sin(\alpha)} \cdot {\sin\left( {\gamma + \delta} \right)}}{{\sin\left( {\pi - \alpha - \gamma - \delta} \right)} \cdot {\tan(\alpha)}}} & {{Eq}.\mspace{14mu} 8}\end{matrix}$

Substitute Eq. 1 and Eq. 2 into Eq. 5:

$\begin{matrix}{\rho = {\sin^{- 1}\left\lbrack {\frac{d \cdot {\sin(\alpha)} \cdot {\sin\left( {\gamma + \delta} \right)}}{D \cdot {\sin\left( {\pi - \alpha - \gamma - \delta} \right)}} - \frac{d \cdot {\sin(\gamma)} \cdot {\sin\left( {\alpha + \beta} \right)}}{D \cdot {\sin\left( {\pi - \alpha - \beta - \gamma} \right)}}} \right\rbrack}} & {{Eq}.\mspace{14mu} 9}\end{matrix}$

Substitute Eq. 7 and Eq. 8 into Eq. 6:

$\begin{matrix}{d = {\quad\frac{D \cdot {\cos(\rho)}}{\frac{{\sin(\gamma)} \cdot {\sin\left( {\alpha + \beta} \right)}}{{\sin\left( {\pi - \alpha - \beta - \gamma} \right)} \cdot {\tan(\gamma)}} + \frac{{\sin(\alpha)} \cdot {\sin\left( {\gamma + \delta} \right)}}{{\sin\left( {\pi - \alpha - \gamma - \delta} \right)} \cdot {\tan(\alpha)}} - 1}}} & {{{Eq}.\mspace{14mu} 10}a}\end{matrix}$

Eq. 10a can also be written:

$\begin{matrix}{d = \frac{\begin{matrix}{D \cdot {\cos(\rho)} \cdot {\sin\left( {\pi - \alpha - \beta - \gamma} \right)} \cdot} \\{{\sin\left( {\pi - \alpha - \gamma - \delta} \right)} \cdot {\tan(\gamma)} \cdot {\tan(\alpha)}}\end{matrix}}{\begin{matrix}{{{\sin(\gamma)} \cdot {\sin\left( {\alpha + \beta} \right)} \cdot {\sin\left( {\pi - \alpha - \gamma - \delta} \right)} \cdot {\tan(\alpha)}} + {{{\sin(\alpha)} \cdot {\sin\left( {\gamma + \delta} \right)} \cdot {\sin\left( {\pi - \alpha - \beta - \gamma} \right)} \cdot \tan}(\gamma)} -} \\{{\sin\left( {\pi - \alpha - \beta - \gamma} \right)} \cdot {\sin\left( {\pi - \alpha - \gamma - \delta} \right)} \cdot {\tan(\gamma)} \cdot {\tan(\alpha)}}\end{matrix}}} & {{{Eq}.\mspace{14mu} 10}b}\end{matrix}$

At this point is can be seen that two independent equations exist here:Eq. 9 and Eq. 10. These can be solved simultaneously through variousnumerical method techniques.

Once the calculations have been completed and both benchmarks have beenentered into remote unit 300, the logic flow arrives at a step 452, inwhich the system set-up routine is now completed. The positions of bothbase units A and B have been “registered” or “mapped” into the virtualfloor plan, which is stored either in the bulk memory circuit 316 of theremote unit 300 (which could be a removable flash memory chip), or isstored in the architect computer 50, which is in communication with theremote unit 300 via its communication port Y (at 320). The system is nowready to locate other points on the floor plan.

It should be noted that, if the two base units 20 and 30 had beenpreviously positioned at the same locations where they currently rest,then in theory, the set-up procedure of the flow chart of FIG. 5 wouldnot be necessary now. However, the user may desire to verify those baseunit positions, to be certain that one of the base units had not beenmoved without knowledge of the user. Their positions can be easilyverified by commanding the two base units to “aim” at the benchmarkpoints, one benchmark at a time. If the base units had not been moved,then the laser light lines projected by laser transmitters 22 and 32will form intersecting lines exactly at the correct physical locationson the jobsite floor surface, and this quickly verifies the set-upparameters.

Referring now to FIG. 6, a flow chart is provided for a routine to finda “known” point on the virtual floor plan. The routine begins at a step500, in which two base units and two known benchmarks have beenestablished on the virtual floor plan of the remote unit 300. The logicflow now is directed to a step 510, in which the user enters coordinatesfor a point of interest. This entry is done via either an input sensingdevice 352 (e.g., a keypad), or via a touch screen display (such asdisplay 342) of the remote unit 300. These coordinates can be enteredusing the virtual floor plan that was on the architect's computer 50,and those coordinates will be automatically translated to a set ofaiming data for the base units that contain the laser transmitters.

In essence, the coordinates for this known point of interest havealready been “predetermined” as far as the virtual floor plan isconcerned; the known point of interest has already been “registered” or“mapped” in the memory of the computer that holds the virtual floorplan. In previous (conventional) layout systems, the difficult part hasbeen to now identify, on the actual physical jobsite floor surface,exactly where that known point of interest is located, so that work maybe performed at the correct position.

The first laser beam of base unit “A” is slewed to aim the laser beam atthe entered coordinates, at a step 512. In a similar manner, a step 514causes the laser beam to be slewed for the base unit “B” to aim at thesame set of entered coordinates. After this has occurred, the two laserplanes from base units A and B will intersect on the floor surface atthe designated coordinates. The user, at a step 516, can now visuallylocate the intersecting point on the floor surface, and can commencework at that point.

The logic flow now arrives at a decision step 520, where it determinesif there will be work at the ceiling level. If not, the logic flow isdirected to a step 530. If the answer is YES, then the user willvisually locate the intersecting point of the two laser planes on theceiling surface at a step 522. The user will now be able to commencework at that point. This would be useful for installing sprinklers,smoke detectors, or lighting fixtures, for example, as per thearchitect's plan.

The logic flow now arrives at a decision step 530, where it determineswhether or not there will be work along a vertical wall. If not, thenthe logic flow is directed to a step 534. If the answer is YES, then theuser will visually locate the intersecting line on the wall surface at astep 532. This is the implied plumb line that exists between the floorand ceiling intersecting points of the two laser planes. Now that a wallsurface has the vertical plumb line visible along the wall's surface,the user can commence work along that line. This can be useful forplacing electrical outlets, or for framing, or even for positioning thewall in the first place.

The logic flow now arrives at a step 534, and the routine is nowcompleted for this location. A decision step 540 now determines whetheror not the user is ready for another point of interest. If not, thelogic flow is directed to a step 542, where this routine is completed.If the user is ready for another point of interest, then the logic flowis directed back to step 510, which allows the user to enter coordinatesfor a new point of interest on the remote unit 300.

An example set of position calculations is provided below. Thiscalculation set describes a method to solve for the aiming angles whenlaying out the location of a known point of interest once the system isset up; it solves for the angles each transmitter must drive to in orderto present a point of interest that is desired to be found. See, FIG. 23for a diagram that illustrates the relationship of physical points andangles involved in the routine for locating a known point of interest.

Definitions

-   -   T1 Transmitter 1    -   T2 Transmitter 2    -   B1 Benchmark 1 (Known point—previously established)    -   B2 Benchmark 2 (Known point—previously established)    -   A1 Axis between the two transmitters

Knowns:

-   -   d Distance between transmitters    -   A:(X_(A), Y_(A)) Coordinates of the Point of Interest to be        Found

Process:

-   -   1) Enter the coordinates of the Point of interest into the        system remote.    -   2) Transmitters 1 and 2 drive to the corresponding angles θ and        ϕ needed to present point A:(X_(A), Y_(A)).    -   3) Visually locate where the planes intersect.        From the Diagram:        a=X_(A) and b=Y_(A)        Solving for θ and ϕ:

$\theta = {\tan^{- 1}\left( \frac{b}{a} \right)}$$\phi = {\tan^{- 1}\left( \frac{b}{d - a} \right)}$

Referring now to FIG. 7, a routine to enter an “unknown” point isprovided as a flow chart. The routine begins at a step 600, in which twobase units and two known benchmarks have already been established on thevirtual floor plan at this step. A step 610 now locates a “new” physicalpoint of interest on a surface that is within the working floor plan.This new point of interest is not already plotted on the virtual floorplan—if it was, it would not be “unknown.” Instead, this new point issomething that the user has decided should be now plotted on the virtualfloor plan, and it is a physical point that the user can actually see,and that he/she wants to now have memorialized within the floor plancomputer files.

After the new point of interest has been physically located at step 610,a step 612 requires the user to aim the laser beam of base unit “A” atthis point of interest. This means that the user must command (ormanually slew) the laser beam directly at the point of interest, so thatthe plane of laser light creates a line along the floor surface(assuming this point is on the floor surface) until that line visuallycrosses the point of interest.

After base unit “A” has been aimed at step 612, a step 614 now requiresthe user to aim the laser beam of base unit “B” at the same new point ofinterest. Again, the laser plane from base unit “B” will create a lineof laser light along the floor surface (again assuming this is a pointon the floor surface), and this creates a visible line that emanatesaway from base unit “B” and, after being properly aimed, the laser lightwill visually cross the new point of interest. At the end of this aimingphase in step 614, both laser planes should now intersect (as visiblelight lines on the floor surface) exactly at the point of interest.

The angular encoders will now have azimuth information that can bestored, and a step 620 enters data from the angular encoders of bothbase units into the remote unit. (This would typically occur via a usercommand entered on the remote unit.) Once the remote unit has this data,a step 622 causes the remote unit to execute a reverse calculation toplot the coordinates for this point of interest on the virtual floorplan. Once that has occurred, the unknown point of interest is now“registered” on the virtual floor plan, and that point of interestessentially becomes a “known” point of interest and thereby can be“found” later, even if the base units 20 and 30 are moved to otherlocations. A step 624 now is reached, at which the routine has beencompleted for this particular location (i.e., at this point ofinterest).

Alternatively, if the base units do not have azimuth encoders, then theywill be equipped with a visual angle scale that the user can see on anupper surface of the base units. After the user has (manually) aimed thelaser transmitter for each base unit (at steps 612 and 614), then he/shemay read the azimuth angular displacement for both laser transmitters,and that information can then be manually entered into the remote unitat step 620 (using its input sensing device 352). Once the remote unithas this data, steps 622 and 624 are performed, as described above.

A decision step 630 now determines whether or not the user is ready foranother “new” point of interest. If not, then the entire routine of FIG.7 has been completed at a step 632. On the other hand, if the user hasanother point of interest to be plotted at this time, then the logicflow is directed back to step 610, in which the user locates that otherphysical point of interest on a surface that is within the working floorplan.

By using the routine depicted in the steps of the flow chart on FIG. 7,a user can easily choose any point of interest on the jobsite that iswithin a non-interrupted view of both laser transmitters in both baseunits. Once the user has located that physical point, it is a simplematter to aim both laser transmitters directly at that point to createtwo intersecting lines of laser light from the laser planes emitted bythe two laser transmitters. This is very easy to do, because the usercan see everything that is going on, assuming the laser transmitters areemitting visible light. Even if the light is infrared, for example, theuser could be utilizing special night-vision goggles to locate thesepoints, if desired. This non-visible light scenario might be quiteuseful for applications that are to occur in the dark, and might evenhave military applications (for plotting positions of mines in aminefield, for example). In non-dangerous situations, aposition-detecting laser receiver could be used instead of night-visiongoggles to locate these points, if desired.

This routine of FIG. 7 can be performed much more quickly than a typicalsurveying function that is being performed countless times on jobsitesusing earlier technology. No type of surveyor's rod is necessary, andsuch a rod would not need to be positioned and plumbed for each newpoint of interest, such as is required in many of the systems usingavailable conventional technology.

If the user selects a point that is not within direct visible range ofone of the laser transmitters, it is a simple matter to move thatparticular laser transmitter to a different location within the virtualfloor plan and re-establish its set-up function using the routineillustrated as a flow chart in FIG. 5. Once the laser transmitter hasbeen placed at a new location, its position can easily be establishedwith benchmarks that are always available on a new jobsite, and onceeverything has been registered with the remote unit, the user candirectly begin to enter unknown points, using the flow chart of FIG. 7.

An example set of reverse calculations is provided below. Thiscalculation set describes a method to solve for the coordinates for thelocation of an unknown point of interest once the system is set up. See,FIG. 24 for a diagram that illustrates the relationship of physicalpoints and angles involved in the routine for entering an unknown pointof interest.

Definitions

-   -   T1 Transmitter 1    -   T2 Transmitter 2    -   B1 Benchmark 1 (Known point—previously established)    -   B2 Benchmark 2 (Known point—previously established)    -   A1 Axis between the two transmitters

Knowns:

-   -   d Distance between transmitters    -   δ Angle measured by transmitter 1 from the axis between        transmitters and the point of interest    -   ϕ Angle measured by transmitter 2 from the axis between        transmitters and the point of interest

Process:

-   -   1) Command each transmitter to place each respective fan beam        over the point of interest.    -   2) Transmitters 1 and 2 measure the angles θ and ϕ.    -   3) Since d is known from the system setup, the coordinates of        point a can be calculated.

From the Diagram:

$y_{0} = \frac{d}{\frac{1}{\tan(\theta)} + \frac{1}{\tan(\phi)}}$

This can be Written:

$y_{0} = \frac{d \cdot {\tan(\phi)} \cdot {\tan(\theta)}}{{\tan(\theta)} + {\tan(\phi)}}$And: $x_{0} = \frac{y_{0}}{\tan(\theta)}$

Further Operating Details

Referring now to FIG. 8, a diagrammatic view is provided for the main“mechanical” components found in a base unit, including a lasertransmitter and a laser receiver. The base unit is generally designatedby the reference numeral 100, and includes a leveling platform at thebottom of the structure, upon which is mounted a rotational unit foradjusting the azimuth angle of the laser transmitter. The levelingplatform includes two leveling motors 142, a level sensor 144 (e.g.,some type of electronic gravity sensor), and a pivot 146. Above theleveling motors 142, are leadscrews 148, and the horizontal levelingplatform is mounted on the top of the leadscrews 148.

It will be understood that a manual leveling platform could be providedwith base unit 100, rather than the “automatic” leveling platformdescribed in the previous paragraph. Such a manual leveling platformcould use a pendulum or a visible bubble, for example, and there wouldbe no automatic gravity sensing device or leveling motor drive.

On the upper surface of the leveling platform is the azimuth motor 162,which has output shaft and a pinion gear 164, which meshes with a spurgear 166. The spur gear has an output shaft that is vertical, which runsthrough an encoder disc subassembly 152 and up to a second wheel or discthat includes a pair of butt cell photosensors 220. The encoder discsubassembly 152 typically has some type of visible markings that can bedetected by an encoder readhead, which is located along the outerperimeter of the encoder disc. On FIG. 8, the encoder readhead isdesignated by reference numeral 154, and the overall angle encodersystem 150 includes both the encoder disc subassembly 152 and theencoder readhead 154. Typical optical encoders have a fixed portion anda rotatable portion, as depicted on FIG. 8 by the two parallel discstructures in subassembly 152.

A laser diode 172 is mounted (in this diagrammatic view) in thehorizontal direction, and it emits a laser light beam through acollimating lens 174, and that laser light travels through a cylinderlens 176 to create an output fan beam 178. The fan beam 178 isdiagrammatically presented on FIG. 8 as a diverging plane of laserlight.

In this arrangement, the azimuth motor 162 turns the aiming direction ofthe fan beam laser plane of light 178, and this simultaneously moves thebutt cell photosensors 220 and a portion of the encoder disc subassembly152. In a typical arrangement, the split between the butt cellphotosensors will be along the same vertical line as the edge view ofthe fan beam laser plane of light 178. However, it should be noted thatthe butt cell photosensors 220 could be somewhat offset from thecenterline of the plane of laser light 178, and the calculations fordetermining positions of various points in the floor layout system couldbe adjusted by those offset calculations, especially fordetermining/establishing an alignment axis. This optional arrangement,sometimes referred to as “characterizing” the photosensors, can make itsomewhat easier to construct the base unit, if desired.

A second photosensor is provided on FIG. 8. This is a “rod” sensor, andis depicted at reference numeral 230. In this rod sensor, however, thereis only a single photocell at 236. Although a typical position-sensingrod sensor would have two photocells (as depicted in FIG. 3), in theconfiguration of FIG. 8, the information being sought only requires asingle photocell. In the base unit 100, the information being sought iswhether or not laser light is impacting the rod sensor cylindricalsurface, and if so, a single photocell at 236 will detect that event. Onthe other hand, if greater sensitivity is desired, or if themanufacturer wishes to use a standard rod sensor that already has twophotocells mounted to the cylindrical rod (one on each end), then astandard rod sensor could be used, as depicted on FIG. 3.

As indicated on FIG. 8, the azimuth motor drive 162 can rotate theentire upper portion of the base unit in the horizontal plane; i.e., therotational axis is essentially vertical, once the leveling platform hasadjusted itself to making the system substantially horizontal withrespect to gravity.

An alternative arrangement could be used to build a lesser expensivebase unit 100. The photosensor 220 could be replaced by a smallreflector that is precisely positioned to be in vertical alignment withthe centerline of the plane of laser light 178. In this alternativeembodiment, the opposite laser transmitter would have to be manuallyaimed at the reflector, when determining an alignment axis. Thiscertainly would be more difficult to set up than the automated procedurethat is described below, but it is possible, particularly forshort-range situations in which the distance between the base units isrelatively small. The laser receivers 24 and 34 could be entirelyeliminated in this alternative embodiment.

Another way to reduce system cost is to eliminate the automatic azimuthaiming platform altogether, and instead rely on manual aiming of thelaser transmitters for both base units. This second alternativeembodiment would save the cost of the azimuth drive (including motor162) and the encoder system 150. Of course, the “aiming” azimuth anglesthen would have to be read manually from an arcuate scale on the baseunit, and these angles would have to be entered manually into the remoteunit by the user every time the laser transmitter is aimed at a newbenchmark point, a known point of interest, or an unknown point ofinterest. The possibility of errors in data entry would increase, evenif the azimuth angles are correctly read in the first place.

Referring now to FIGS. 9-13, a set of illustrations is provided to morereadily demonstrate the ease of use of the system being disclosedherein. In FIG. 9, a first step for aligning the axes of the two lasertransmitters is depicted. The laser transmitters are part of the baseunits 20 and 30, which are mounted on tripods in FIG. 9. A user,generally designated by the reference numeral 45, is depicted as holdinga hand-held remote unit 40, within the confines of a space (or room)700. The room 700 has a ceiling surface 710 and floor surface 712.

The laser transmitter at base unit 20 emits a laser fan beam, which hasan upper angular limit line at 722 and a lower angular limit line at724. The other laser transmitter at base unit 30 also emits a fan beamof laser light, and has an upper angular limit line at 732 and a lowerangular limit line at 734. The object in this step of FIG. 9 is to alignan axis 740 between the two laser transmitters. The methodology for adetailed alignment procedure is described below, in reference to FIGS.14-19. At this point in the description, it will be assumed that thealignment axis 740 is being determined by this procedure.

FIG. 10 illustrates the next step, which aligns the two lasertransmitters to a first benchmark point (referred to on FIG. 10 as“Benchmark 1”). In FIG. 10, the interior space (or room) is referred toas reference numeral 701. The two laser transmitters have been aimed atthe point of interest that is Benchmark 1, and is designated by thereference numeral 752. The two base units 20 and 30 have either hadtheir lasers manually aimed by the user, or automatically adjusted bythe user using the remote unit 40, if azimuth positioning motors andencoders are available on base units 20 and 30. After the two laserplanes have been aimed so that they will intersect the first benchmarkat 752, the laser planes will have an appearance as illustrated on FIG.10. The laser plane from the fan beam laser transmitter of base unit 20will again have angular limit lines 722 and 724, but will also produce avisible line along the ceiling at 726, and a similar visible line alongthe floor surface at 728. In a similar manner, the laser transmitterproducing the fan beam from base unit 30 will emit angular limit lines732 and 734, and also produces an upper visible line along the ceilingat 736 and a lower visible line along the floor surface at 738.

It will be understood that, as used herein, the terms “visible light” or“visible laser light” refer to laser light beams that are eitherdirectly visible by the human eye (i.e., having a wavelength in therange of approximately 430 nm to 690 nm), or refer to laser beams thatare somewhat outside of the above “normal” range of visible acuity forhuman eyes, and the user is being aided by some type of special lenses.For example, the laser transmitters described herein could produceinfrared (IR) laser light beams if desired, and the user could bewearing night-vision goggles; in that situation, the laser light beamswould appear to be “visible” to that user, which is more or lessnecessary to properly use the alignment and location features of thesystem described herein.

The two lower laser plane edges 728 and 738 will intersect exactly atthe benchmark point 752, after the two laser transmitters have beencorrectly adjusted for their angular position along the azimuthdirection, and the user will be able to visibly see that intersectionpoint. Moreover, the two laser planes will intersect along a verticalline 750, which will be a plumb line if the two base units have beencorrectly leveled. This laser line of intersection 750 will actually bevisible if a solid object, or some type of smoky substance, ispositioned along the line itself. At the top of the laser light line 750will be another visible intersection of “horizontal” lines along theceiling, which will be described below, in greater detail.

The third step is to align the laser transmitters for the two base unitsto the second benchmark point, which is referred to on FIG. 11 as“Benchmark 2” The interior space (or room) is designated at thereference numeral 702 in FIG. 11. The user now is required to move theangular positions of both laser transmitters for the base units 20 and30 so that they are aimed at the second benchmark, which is designatedat reference numeral 762. Both laser transmitters continue to emit aplane of laser light, and the fan beam thereby produced has divergenceangles that are represented by the lines 722, 724, 732, and 734.Furthermore, there will be upper and lower visible lines along theceiling surface and floor surface, which again are designated by theline segments 726, 728, 736, and 738.

After the two laser transmitters have been properly aimed at the secondbenchmark 762, the lower visible lines of the two laser planes willintersect exactly at benchmark 762, and the user will be able to visiblysee that intersection point.

It will be understood that, as used herein, the phrase “intersectexactly” at a specific point on a surface means that the user hasadjusted the laser transmitters so that their emanating laser fan beamsproduce light lines that appear to be precisely crossing that specificpoint. Of course, there will likely be some small tolerance of error,and it is up to the user to make the proper adjustments in aiming thebase unit laser transmitters so that the light lines are as close to“exactly” crossing right at the proper location. Since the laser lightlines have a discernable width, the user cannot literally align thelaser beams within some imperceptible tiny distance, and thus, therewill likely be a very small tolerance of error in such “exact” positionsof the laser transmitter azimuth angles. However, this is a very smallerror indeed, and moreover, the user will quickly become very good atmaking these azimuth position changes of the laser transmitters suchthat any such errors will essentially be negligible.

As in the case of FIG. 10, there will also be an intersecting verticalline between the two laser planes, and this intersecting line isrepresented at the reference numeral 760 on FIG. 11. This intersectingline 760 is a plumb line, so long as the two laser transmitters havebeen properly leveled.

After both benchmark points have had their coordinates entered into theremote unit 40 (as per FIG. 10 and FIG. 11), the set-up of the systemhas been completed. Now the user will be able to enter other coordinatesof interest into the remote unit 40, and cause the laser transmitters toautomatically aim at those coordinates (assuming the laser transmittersare motorized and have angular encoders). FIG. 12 illustrates such asituation, in which the user has entered the coordinates of a floorpoint designated by the reference numeral 772 on FIG. 12. The space (orroom) is designated at the reference numeral 703 on FIG. 12. The lasertransmitters have been aimed so that their fan beams each produce aplane of laser light that is vertical, and both of these planes of laserlight intersect exactly at the point 772 along the floor surface 712.There will also exist a vertical line of intersection between the twolaser planes at the reference numeral 770. This will be a plumb line, asdescribed before, so long as the laser base units 20 and 30 have beencorrectly leveled. More importantly, the two laser transmitters need tooutput laser planes that are substantially vertical with respect togravity; if that correctly takes place, then the implied line 770 willalso be substantially vertical with respect to gravity.

Since the plumb line 770 exists as a vertical line directly above thefloor point 772, there will also be visible to the user a ceilingtransfer point that is designated by the reference numeral 774. The userwill see a pair of intersecting lines at point 774, which are producedby the two upper edges of the laser planes from the laser transmittersof base units 20 and 30. These are the upper edge lines of the fan laserbeams along the line segments 726 and 736, which follow along thesurface of the ceiling 710. This provides the user with a virtuallyinstantaneous transfer point along the ceiling surface, every time theuser first designates a floor point of interest. The ceiling transferpoint 774 is automatically plumb above the floor point 772, since theimplied line 770 is truly plumb. This system allows the buildingdesigner to lay out devices that are to be installed in the ceiling byusing the coordinates on a two-dimensional floor plan, if desired.

The technology disclosed herein automatically can take floor points andtransfer those coordinates to the ceiling; furthermore if the buildingplan was a three-dimensional plan, then a ceiling set of coordinatescould first be entered instead of a floor set of coordinates. In thatmode of operation, the two laser transmitters of base units 20 and 30will still be able to slew automatically so that their laser fan beamswill intersect the ceiling set of coordinates instead of the floor setof coordinates. The final appearance will be the same, just like what isillustrated in FIG. 12. The only difference will be that the ceilingpoint was determined first, instead of the floor point. There will stillexist a plumb line 770 after the ceiling point has been laid out.

Referring now to FIG. 13, the ability of the system disclosed herein tocreate a vertical plumb line of laser light will be used advantageously.A space (or room) 704 is depicted on FIG. 13, and the two lasertransmitters of base units 20 and 30 have been aimed at a floor point782 that is located just along the edge of one of the walls, which isdesignated by the reference numeral 714. The laser fan beams will createa visible plumb line of laser light 780 that will be visible along thesurface of the wall 714. There also will exist a ceiling intersectingpoint at 784 that is the top point of the line segment 780, which makesup this intersecting line between the two planes of laser light. For theimplied laser plumb line 780 be visible along the wall surface, the wallmust be positioned at or fairly close to the intersecting point 782;this can be termed a “proximal” relationship—the wall must have itssurface 714 proximal to the point 782, or the intersecting line of laserlight 780 will “miss” the wall surface, and not be visible on that wallsurface. Of course, the wall itself must be fairly plumb, or the plumbline 780 will not properly appear along the wall's surface.

As discussed in the previous paragraph, if a two-dimensional floor planis available, then the user can start with the floor intersecting point782 as the point of interest. On the other hand, if a three-dimensionalset of floor plans is available, and if the ceiling intersecting point784 has coordinates that are available to the user, then that pointcould be used to cause the laser transmitters to be aimed as depicted inFIG. 13.

After the plumb line 780 appears along the wall surface 714, the usercan use that plumb line to help align and set walls, such as studdedwall. In addition, once the walls have been installed, the verticalplumb line 780 can be used to help locate the positions for installationof wall outlets or HVAC ducts or vents, and other similar devices thatare placed in walls of buildings.

Referring now to FIGS. 14-19, an example of a methodology forestablishing an alignment axis between two base units is provided.Referring now to FIG. 14, the two base units 20 and 30 are emittingvertical planes of laser light in a fan beam shape, in which the planeof laser light for base unit 20 is designated by the reference numeral60, and the plane of laser light from base unit 30 is designated by thereference numeral 70. As can be seen in FIG. 14, laser light planes 60and 70 intersect one another, but they are not aligned, nor do theyintersect the opposite base unit.

In FIG. 14, base unit 20 has a positioning photosensor at 64, whichtypically can be a “butt cell” set of photocells that are preciselyaligned to the center of the emitted laser fan beam. Base unit 20 has asecond photosensor at 62 that comprises a photocell and a cylinder lens.The cylinder lens extends vertically above the top of the base unitstructure (this is similar to element 230 on FIG. 8), and the photocellis attached at one end of the cylinder lens (which is similar to thephotocell 236 on FIG. 8). This photocell and cylinder lens combination62 is roughly aligned to the rotation center of base unit 20. (It doesnot need to be precisely aligned. Photosensor 62 provides “gross”alignment sensing capability for detecting the laser beams of the otherlaser transmitter, from base unit 30.)

In a similar fashion, base unit 30 also includes a positioningphotosensor 74 which typically can be a “butt cell” array of photocells,which are precisely aligned to the center of the emitted laser fan beam70. (Note: this “precise” alignment could include characterizing thearray of photocells to correct for any offset, in case the position ofthe laser beam output and the photosensor's null point are not perfectlyaligned.) Also, base unit 30 includes a cylinder lens and photocellcombination at 72, which is roughly (not precisely) aligned to therotation center of that base unit. Photosensor 72 provides “gross”alignment sensing capability for detecting the laser beams of the otherlaser transmitter, from base unit 20.

Referring now to FIG. 15, the user has entered a command so that eachbase unit will begin to rotate. The purpose of this rotation is to havethe cylinder lens/photocell combination (either 62 or 72) detect thelaser beam from the other base unit. In FIG. 15, it can be seen thatboth laser fan beams have changed position, but neither fan beam 60 or70 are intersecting the other base unit. Laser fan beam 60 is rotatingin the direction of an angular arc line 66, while base unit 30 has itslaser transmitter beam 70 rotating in the direction of an angular line76.

Referring now to FIG. 16, the laser fan beam 70 has intersected thevertical photosensor 62 of base unit 20. When this occurs, base unit 30can stop rotating its fan beam 70, because it is now roughly in thecorrect position. However, the fan beam 60 from base unit 20 still needsto continue rotating in the direction 66. In FIG. 17, the fan beam 60 isstill rotating from base unit 20, but has not yet intersected base unit30. The fan beam 70 from base unit 30 has stopped, and is stillintersecting the vertical photosensor 62.

Referring now to FIG. 18, the laser fan beam 60 from base unit 20 hasintersected the photosensor 72 of base unit 30, and the lasertransmitter at base unit 20 now will stop rotating. At this time, bothfan beams 60 and 70 are roughly aligned with the opposite base units 30and 20 respectively.

Referring now to FIG. 19, the positioning photocells 64 and 74 now comeinto play. Assuming these two photocells each comprise a pair of buttcell photosensors, they will have a deadband width between the twophotosensitivity areas of the butt cell arrangement, and this deadbandwidth is the desired position that will be sought by the two laser fanbeams 60 and 70. Using the positioning photocells 64 and 74, the laserreceivers on the two base units 20 and 30 will be able to determine theexact position of the laser strike of the fan beams 60 and 70 within avery small tolerance. The output signals from the laser receivers can beused to command the azimuth positioning motors of both lasertransmitters for the base units 20 and 30 to move in small amounts untilthe vertical edge of the laser planes 60 and 70 are striking the buttcell deadband positions.

The butt cell deadband width can be made quite small, perhaps as smallas 0.005 inches, if desired. In FIG. 19, the two laser transmitters arerotated iteratively until each of their fan beams are striking withinthe deadband width of the butt cells on the opposite base unit. Thiswill now provide a very precise alignment axis between the two baseunits 20 and 30.

Another benefit of the technology disclosed herein is illustrated onFIGS. 20 and 21. FIG. 20 illustrates a conventional (prior art) laserpointing system that is currently used for floor layout procedures. Thisprior art system is generally designated by the reference numeral 800,and it includes a laser transmitter 810 that is mounted on a tripod, andthis assembly is placed on a floor surface 812. This pointing lasersystem is designed to literally point its laser beam 820 directly at aparticular spot on the floor surface 812, and that spot visuallydesignates the point of interest for the user. This system will work, solong as the floor surface is actually flat and horizontal within thetolerance required for the laser pointer system to successfullydesignate the point of interest.

However, if there is any kind of unevenness in the floor, such as adepression that is designated by the reference numeral 814, then theaccuracy of laser pointing system 800 is completely thrown off. It willbe understood that the depression 814 could just as easily be aprotrusion in the floor surface, and that would also negatively impactthe accuracy of the system 800.

The reference numeral 822 designates the true position for the point ofinterest on the floor surface where laser beam 820 is attempting todesignate that position. However, because of the depression in the floorat 814, the projected point on this uneven surface is at a differentphysical location in the horizontal direction, which is designated bythe reference numeral 824. This causes a position error that isdesignated by the reference numeral 830. Depending upon the horizontaldistance between the true position 822 and the position of the lasertransmitter 810, the position error 830 can be significant, and willrender the system useless for its intended accuracy.

Referring now to FIG. 21, the technology disclosed herein can be usedwith two laser transmitters, as described above, and this type of systemis generally designated by the reference numeral 900. A first lasertransmitter is at 910, and a second laser transmitter is at 911. Lasertransmitters 910 and 911 are both mounted on tripods, and both emit alaser fan beam (in this example), in which the fan beam for lasertransmitter 910 is designated by the reference numeral 920, and the fanbeam for laser transmitter 911 is designated by the reference numeral921.

Both laser transmitters are positioned on a floor surface, which isgenerally designated by the reference numeral 912. A point of interestis entered into the system that controls the azimuth of both lasertransmitters 910 and 911, and therefore, they will be aimed at thecorrect location on the floor surface. On FIG. 21, the true position ofthe point of interest is designated by the reference numeral 922. It sohappens that the point of interest 922 lies in a depression in thefloor, which is designated by the reference numeral 914. However, thevertical planes of the two laser fan beams 920 and 921 intersect in avertical plumb line at 950, and this plumb line will run from itsuppermost limit at the top edge of the laser fan beams 920 and 921 downto its lowermost limit (along line 950), which intersects the floorsurface in the depression 914, at a point 924.

Because of the way system 900 operates to create the plumb line 950, theindicated position of the point of interest at 924 will fall exactly atthe true position of the point of interest at 922. Therefore, no errorwill occur between the true position 922 and the point that is projectedonto the floor surface 924, even when that projected point falls withina depression, such as the depression 914. This will also be true if,instead of a depression, there is a protrusion in the floor surface.This feature is a very significant advantage provided by the technologydisclosed herein.

Enhanced Capability Base Unit

Referring now to FIG. 25, an alternative embodiment for an exemplaryenhanced capability base unit is disclosed in a block diagram format.The base unit #A is generally designated by the reference numeral 1020,and includes a laser transmitter 22, a laser receiver 24, and an aimingplatform 26, similar to what was disclosed in FIG. 1 for the base unit20. In addition, base unit 1020 includes a distance measurer device1028.

In a similar fashion the base unit #B, generally designated by thereference numeral 1030, includes a laser transmitter 32, laser receiver34, and an aiming platform 36, much like the base unit 30 on FIG. 1. Inaddition, base unit 1030 includes a distance measurer 1029.

FIG. 27 illustrates an exemplary alternative embodiment base unit withenhanced capabilities, generally designated by the reference numeral1100. It is similar in structure and function to the base unit 100 thatwas illustrated on FIG. 8. However the alternative embodiment base unit1100 includes a laser distance measurer 1028, which is the same devicethat was shown diagrammatically on FIG. 25. The laser distance measurer1028 is mounted on the rotating platform 152, and its output laser beam1194 is aimed to be co-planar with the fan beam 178. It will beunderstood that various types of distance measuring instruments could beused for the device 1028, and it does not necessarily need to be a“laser” distance measuring device. In this description herein, thedistance measuring device (DMD) will often be referred to as a“laser”-type device, because such devices are well known in thesurveying and construction industry. Moreover, a laser distancemeasuring device would typically work quite well for use in thetechnology disclosed herein; such devices are often referred to as“laser distance meters.”

In general, a laser distance meter is a device which includes amodulated light laser transmitter, a modulated light laser receiver, anda processing circuit that determines a flight time of a modulated lightlaser beam that is emitted by the directional laser transmitter untilits reflected (still modulated) light is received by the laser receiver.The processing circuit then converts the flight time into a distance tothe aimed at target. An example of an exemplary laser distance meter isa Trimble Model No. HD100.

In the illustrated embodiment of FIG. 27, there is a laser diode 172that produces a light beam, and after being aimed through a collimatinglens 174 and a cylinder lens 176, a fan beam is emitted. Such a fan beamis a purely static light plane, and is well suited for use in thetechnology disclosed herein. It should be noted, however, that othertypes of laser beams can be used in the technology disclosed herein, andwith good results. For example, a rotating laser beam could be used (inwhich a laser light line is emitted) which rotates along a verticalplane and creates the illusion of a static vertical fan beam, althoughthe laser light beam is actually constantly moving as it sweeps throughthe vertical plane. It will be understood that a dithering laser beam isa form of a rotating laser beam, and such a dithering laser beam couldbe used to create the illusion of a static vertical fan beam; adithering laser beam would not rotate along an entire circle of 360degrees, but instead would rotate back and forth along a narrower arc,while sweeping through its angular movements to create a vertical planeof laser light.

Dithering assumes that the source is a laser spot, or a short linesegment, as opposed to a line. A rotating laser also uses a laser spotsource. A rotating laser spot, being incident on a surface at somedistance, traces out a line around the entire perimeter (which alsodescribes a “plane” of laser light). For the same rotor speed, asdistance increases the spot's linear speed necessarily increases, whichreduces the perceived brightness of the line the laser beam is tracingout. One solution for this loss of perceived brightness is to “dither”the beam.

Dithering the laser beam is accomplished by determining limits of thesubtended arc desired and then oscillating the beam within theseextents, back and forth, so as to trace out a line that is significantlyshorter than the full perimeter provided by a (360 degree) rotatinglaser. The effect is to sweep the beam in the area of interest (i.e.,where the work is to be performed) in a shorter path length and slowerlinear speed, thus increasing the perceived brightness of the linelocally traced out. Note that the traced length, being shorter than thefull 360 degree perimeter, allows for a slower linear speed of the beamat potentially the same frequency (refresh rate).

It will be understood that, as used herein, the terms “laser lightplane” and “laser fan beam” (or simply “fan beam”) will refer to one ofat least the following three situations: (1) a purely static plane oflaser light that literally fans out optically in real time from sometype of spreading lens (such as the cylinder lens 176); (2) a rotatingbeam of laser light that, in a given instant creates a single line ofphotons that is aimed at only one angular position at that instant, butover an entire operating cycle of rotational movement, describes anentire circular arc that effectively creates a laser “plane” of photons,and over a fairly brief period of time has the appearance of creating astatic fan beam over the entire 360 degrees of a circle; or (3) adithering beam of laser light that, in a given instant also creates asingle line of photons that is aimed at only one angular position atthat instant, but over an entire operating cycle of back and forthmovement, describes an arc of less than 360 degrees that alsoeffectively creates specific sector of a laser “plane” of photons, andover a fairly brief period of time has the appearance of creating astatic fan beam over the entire prescribed sector (i.e., over less than360 degrees of a circle). In terms of real time operation, any one ofthese methodologies for generating such a laser fan beam will, forpractical uses on a jobsite, create an apparent static plane of laserlight. Such an apparent static plane of laser light is not dependentupon having a narrow laser beam positioned at a precise linear directionat a specific moment in time, for the purpose of working with other“moving” laser beams (or other electronically-generated signals) toestablish some type of positional alignments, such as those used incertain prior art positional-sensing or positional-indicating systems.

Referring now to FIG. 26, a block diagram of the alternative (enhancedcapability) base unit 1100 of FIG. 27 is depicted. Most of thecomponents on FIG. 26 were also included in the base unit 100 that wasdepicted on FIG. 2. A distance measurer device (DMD), generallydesignated by the reference numeral 1180, is included in the base unit1100. Distance measurer 1180 communicates with the microprocessor 110through the input/output circuit 116. The distance measurer 1180includes a laser driver circuit 1182 and a laser beam receiver interfacecircuit 1184. The laser driver 1182 provides current for a laser lightsource 1190, which emits the light beam 1194 (as shown on FIG. 27). Aphotosensor 1192 receives the reflected laser light (from light beam1194), and the current output by the photosensor 1192 is directed to thelaser receiver interface circuit 1184. After appropriate amplificationand possible demodulation, that signal is sent through the I/O circuit116 to the microprocessor 110. In this manner, the DMD 1180 candetermine an accurate distance between the base unit 1100 and a targetthat light beam 1194 is reflected from, back to the photosensor 1192.

It should be noted that FIG. 25 does not include an architect computer,although one could (optionally) be used in such a system. However, usingthe enhanced capability base units of FIG. 25 and FIG. 27, the user doesnot require an architect computer. In fact, the user will be creatinghis or her own new virtual floor plan of an existing “built-out” roomwhen working with this equipment, using a remote unit as a monitor andgenerating the virtual floor plan from information derived by the baseunits, and the new virtual floor plan will be resident on the remoteunit, not on an architect's computer. On the other hand, once a newvirtual floor plan is created by the user, that virtual floor planoptionally could be downloaded onto a separate architect computer, ifdesired.

Referring now to FIGS. 28-32, an example of a methodology forestablishing an alignment axis between two base units is provided,viewed from the perspective of a human user working within a room orspace on a jobsite. On FIG. 28, there is a human user 45 holding awireless remote unit, generally designated by the reference numeral 40.This wireless remote unit has a radio antenna 44, which could also be ofsome other type of communications hardware, if desired. The wirelessremote also has a display 342, which preferably is a touch screendisplay so that the user can enter commands directly on the display. Ifa non-touch screen display is used, then some type of keypad entrydevice would be desired.

On FIG. 28, the user 45 is standing in a room or a space underconstruction, in which the ceiling of the room is designated at thereference numeral 1210, the floor surface is at reference numeral 1212,a left-side wall (typically vertical) is at reference numeral 1214, afront wall is at reference numeral 1216 and a right-side wall is atreference numeral 1218. There are two base units 20 and 30 that areresting on the floor surface 1212.

The user may place the base units 20 and 30 at any desired positions onthe floor surface 1212. In this example methodology starting on FIG. 28,no benchmark points have been established as of yet, and there is novirtual floor plan resident on the remote unit 40. The base units willtypically have the circuitry as described on FIG. 1, along withassociated sensors, including a photosensor 62 for the first base unit20, and a photosensor 72 for the second base unit 30. The next fewfigures will describe a methodology for establishing an axis between thetwo laser transmitters of base units 20 and 30, much like what wasdescribed above in reference to FIGS. 14-19.

Referring now to FIG. 29, base unit 20 is emitting a vertical plane oflaser light in a fan beam shape, in which the upper edge of the fan beamis designated at the line 1222, and the lower edge of the fan beam isdesignated at the line 1224. The lower edge of the fan beam is seen as avisible line that travels across the floor surface at 1212, which isdirected at various angular positions as the laser transmitter rotateson base unit 20. On FIG. 29, the first position of the laser light lineon the floor surface is illustrated at 1225, and then as the fan beamrotates in the direction of arrow 1228, a later line of laser lightappearing on the floor surface is illustrated at 1226, and a yet laterline of laser light is illustrated at the line 1227. When the fan beamfrom base unit 20 impacts the photocell 72 of the base unit 30, acommand is sent to the base unit 20 to stop its rotation of the laserfan beam, so it stops its movement while impacting the photosensor 72.

As noted above, base unit 20 has a positioning photosensor at 64, whichtypically can be a “butt cell” set of photocells that are preciselyaligned to the center of the emitted laser fan beam. Base unit 20 has asecond photosensor at 62 that comprises a photocell and a cylinder lens.The cylinder lens extends vertically above the top of the base unitstructure (this is similar to element 230 on FIG. 8), and the photocellis attached at one end of the cylinder lens (which is similar to thephotocell 236 on FIG. 8). This photocell and cylinder lens combination62 is roughly aligned to the rotation center of base unit 20. (It doesnot need to be precisely aligned. Photosensor 62 provides “gross”alignment sensing capability for detecting the laser beams of the otherlaser transmitter, from base unit 30.)

As discussed above, base unit 30 also includes a positioning photosensor74 which typically can be a “butt cell” array of photocells, which areprecisely aligned to the center of the emitted laser fan beam 70. Baseunit 30 also includes a cylinder lens and photocell combination at 72,which is roughly (not precisely) aligned to the rotation center of thatbase unit. Photosensor 72 provides “gross” alignment sensing capabilityfor detecting the laser beams of the other laser transmitter, from baseunit 20.

As depicted on FIG. 29, the user enters a command so that base unit 20will rotate its laser fan beam transmitter. The purpose of this rotationis to have the omni-directional photocell 72 detect the laser beam atthe other base unit 30. The laser fan beam from base unit 20 is rotatingin the direction of an angular arc line 1228, as discussed above. Oncethe laser fan beam has intersected the vertical photosensor 72 of baseunit 30, base unit 20 can stop rotating its fan beam, because it is nowroughly in the correct position.

There also is a vertical plane of laser light in a fan beam shape beingemitted by the other base unit 30, and it is desired for that fan beamto impact the photosensor 62 of base unit 20. This situation is depictedon FIG. 30. The top edge of the fan beam emitted by base unit 30 islocated along the line 1232, and the bottom edge of this laser fan beamis located along the line 1234. The fan beam laser plane emitted by baseunit 30 will create a line along the floor surface 1210, starting at aposition 1235, and then as the line rotates in the direction of thearrow 1238, the visible laser light line changes position to the line1236, and finally to the line 1237, where it impacts the photosensor 62of base unit 20.

On FIG. 31, the laser fan beam 60 from base unit 20 has intersected thephotosensor 72 of base unit 30, and the laser transmitter at base unit20 now will be commanded to stop rotating. At this time, both fan beams(at lines 1227 and 1237) are roughly aligned with their opposite baseunits 30 and 20 respectively.

Referring now to FIG. 31, the null-position photocells 220 (see FIG. 8)now come into play. Assuming these null-position photocells 220 comprisea pair of butt cell photosensors, they will have a deadband widthbetween the two photosensitivity areas of the butt cell arrangement, andthis deadband width is the desired position that will be sought by thetwo laser fan beams of base units 20 and 30. Using the null-positionphotocells 220, the laser receivers 24 and 34 on the two base units 20and 30 will be able to determine the exact position of the laser strikeof the fan beams within a very small tolerance. The output signals fromthe laser receivers can be used to command the azimuth positioningmotors of both laser transmitters for the base units 20 and 30 to movein small amounts until the vertical edge of the laser planes 60 and 70are both striking the butt cell deadband positions.

The butt cell deadband width can be made quite small, perhaps as smallas 0.005 inches, as noted above. In FIG. 31, the two laser transmittersare rotated iteratively (back and forth) until each of their fan beamsare striking within the deadband width of the butt cells on the oppositebase unit. This will now provide a very precise alignment axis betweenthe two base units 20 and 30.

On FIG. 31, a vertical line 1239 can be seen striking the base unit 20.In the inset view of FIG. 31, it can be seen that the increments ofmovement of the rotation of the laser fan beam emitted by base unit 30can be made smaller and smaller, particularly after the fan beam beginsstriking the omni-directional photosensor 1262. Once the fan beamimpacts the photosensor 1262, the fine-positioning photosensors (e.g.,null-positional butt cell photosensors) can take over the positioningcommands for the base unit 30, with regard to which direction it shouldrotate its laser transmitter. As stated above, these commands can bemade in smaller and smaller positioning increments, and if the target isovershot, then the rotation direction can be reversed from that of thearrow 1238, until the deadband of the butt cells has been targeted. Oncethat occurs, then both fan beams emitted by base units 20 and 30, shouldbe in the same alignment plane, and an alignment axis 1240 has becomeestablished, as depicted in FIG. 32.

In greater detail, the positioning commands that are sent to and fromthe base units 20 and 30 will probably be transmitted through the remoteunit 40. However, it is also possible for the base units to talkdirectly to one another, if that option is selected by the designer ofthe equipment. Yet another option is to allow the user to manually pointthe laser transmitters at the opposite base unit, and if done withsufficient accuracy, that manual operation situation would eliminate theneed for an omni-directional photosensor on top of the base units. Ofcourse, this last option would eliminate many of the nice features ofusing automatic control of the base units, which otherwise is providedby the technology disclosed herein.

In a preferred mode of controlling the base units, a typical operationwould be causing the base unit 20 to rotate its fan beam until theomni-directional photosensor 72 on base unit 30 eventually receives thatfan beam. When this occurs, base unit 30 will send a message to theremote unit 40 that it is now sensing the fan beam from base unit 20.The remote unit 40 quickly sends a message to base unit 20, so that thebase unit 20 will stop rotating its fan beam. At that point, the fineadjustment of the null sensing array (e.g., the butt cells) will be usedto sense the exact relative position of the fan beam as it impacts baseunit 30, and base unit 30 will send corresponding information throughthe remote 40 (to then be transmitted to base unit 20), instructing baseunit 20 which direction it should rotate its laser fan beam. Eventuallythe fan beam emitted by base unit 20 will reach the null position onbase unit 30, and when that occurs, a command will be sent (typicallystarting at base unit 30) to base unit 20 instructing it to stop movingits rotatable laser transmitter, and its fan beam will then be aimeddirectly at the deadband of the null-position sensor of base unit 30.

It should be noted that a very precise omni-directional axis sensormight be developed that could eliminate the need for the butt cellarray. However, this would require a quite precise omni-directionalsensor, in which the characteristic response curve would need to exhibita relatively sharp change in signal versus the angle of incidence of thelaser light beam as it impacts the sensor itself. Some signal processingmight also be usable to improve the overall characteristics of such anomni-directional sensor for this purpose. It will be understood that acertain amount of fine alignment is needed for the axis to beestablished between the two base units 20 and 30. Otherwise, the resultson the jobsite will be diminished.

Referring now to FIG. 33, the human user 45 is again using a remote unit40 and two base units 20 and 30. In this figure, the alignment axisbetween the two base units has already been established. There are twosurveyed points, also called “benchmarks,” that are known to theblueprint, but which are not known yet to the remote unit virtual floorplan. These surveyed points are designated on FIG. 33 at 1252 and 1262,for benchmark 1 (B1) and benchmark 2 (B2).

Referring now to FIG. 34, both base units are aimed at the firstbenchmark at point 1252. The fan beam emitted by base unit 20 has aupper edge at 1222, and lower edge at 1224. These two edges areintercepted by the floor and ceiling, at the lines 1226 and 1228,respectively. As can be seen on FIG. 34, the laser line 1228 intersectsthe benchmark 1 surveyed point at 1252.

The fan beam emitted by base unit 30 has an upper edge at 1232 and alower edge at 1234. It produces light lines along the ceiling and floorat 1236 and 1238, respectively. As can be seen on FIG. 34, the lightline 1224 intersects benchmark 1 (at 1252), and thereby creates an “X”shape of laser light lines intersecting at benchmark 1. In addition,there is an intersecting vertical line of laser light at 1250 created bythe two laser planes from the two fan beams. If a piece of paper (orother solid object) is held in a position to be intercepted by line1250, the X shape of the two fan beams would show on that piece of paperto indicate a point along that virtual line of laser light.

Referring now to FIG. 35, the two base units have been aimed at thesecond benchmark, at the point 1262. The fan beam emitted by base unit20 again has an upper edge at 1222 and a lower edge at 1224, with aceiling line at 1226 and a floor line at 1228, which intersects thebenchmark 2 position at the point 1262. The fan beam emitted by the baseunit 30 again has an upper edge at 1232 and a lower edge (that cannot beseen in this view), with an upper ceiling laser light line at 1236 and alower floor laser light line at 1238 which both intersect the benchmark2 position at the point 1262. Therefore, an “X” shaped pair of laserlines intersect at the benchmark 2 point. There will again be anintersecting vertical line of laser light at 1270 that is above thebenchmark 2 position. A piece of paper or other solid object held atthat position to intercept light line 1270 would reflect that X-shapedintersection.

After the procedure of FIG. 34 and FIG. 35 is performed, the azimuthangles at each base unit are recorded, which is easily done at themonitor (or remote unit) 40.

Once the angles are recorded into the remote unit 40, the two benchmarkcoordinates are also entered into the monitor. Knowing the coordinates,the remote unit can calculate the distance D1 (as seen on FIG. 35),which is the distance between the two benchmark positions. Once thatinformation is known by the remote unit, then the virtual positions ofthe two base units can be calculated, and then all information can bescaled.

As an alternative that will be discussed in greater detail below, ifonly the distance D1 was known, but not the actual coordinate positionsof the two benchmark points, all of the information relating to thepositions of the base units, including the alignment axis, could bescaled simply by knowing the azimuth angles of the two benchmark points(along with the physical distance therebetween).

Routine to Create Benchmarks

Referring now to FIG. 36, another method for setting up on a jobsite isillustrated, starting with the user 45 positioning two base units 20 and30 on the floor surface 1212 of the room (see step 1500 on the flowchart of FIG. 51). In this new methodology, there are no establishedbenchmarks as of yet, and there is no virtual floor plan in the remoteunit 40. After positioning the base units at any desired locations onthe floor 1212, the user will perform the steps necessary to establishthe alignment axis between the two base units, as described above inconnection with FIGS. 28-32 (see step 1502).

Since there are no previously established benchmarks on this jobsite,but there is an actual room with walls and corners, the user will now beable to create a virtual floor plan in the monitor or remote unit 40 byuse of the existing physical features. For example, the existing cornersof the room can be used for this purpose.

So the next step in this methodology will be to point both base units 20and 30 at one of the corners (see step 1504). In FIG. 36, both baseunits are aimed at the corner 1282, and the fan beams emitted by bothbase units will shine directly on the corner itself, along a verticalline 1280. Moreover, the bottom edge line of the fan beam emitted bybase unit 20 will be aimed directly at the corner along the floorsurface; this fan beam will show a visible light line 1228 thatintersects the corner point 1282. Similarly, the fan beam being emittedby base unit 30 will have a visible laser light line 1238 that runsalong the floor surface 1212, also intersecting the same point 1282. Ifdesired, the fan beam of one of the base units can be turned off whilethe other base unit is being aimed, to more precisely direct each of theindividual fan beams of each of the base units.

Once both base units are correctly aimed at the corner point 1282, theazimuth angles will be recorded at the remote unit 40 (see step 1506).If desired, this corner can become the origin point (having coordinates0,0) for the virtual floor plan that will now be established on theremote unit 40. It will be understood that other coordinates could beentered for this point, if desired. In effect, the corner point 1282 isbecoming a first benchmark for this virtual floor plan. It is not somuch a “surveyed point” like one would normally expect to see on ablueprint plan, but in reality it is a physical point that can be usedfor the purposes of establishing a virtual floor plan in the remote unit40.

Referring now to FIG. 37, the two base units are now aimed at adifferent point (see step 1510), and in this situation it is anothercorner point, at 1292. This will be done by aiming the fan beams of bothbase units 20 and 30 directly at the corner point 1292 and this shouldbe visible by a vertical light line 1230 that runs directly along thecorner, above the corner point 1292. Both laser transmitters on the baseunits should be emitting a fan beam that establishes a visible lightline along the floor; for base unit 20 this will be laser light line1228 that will directly intersect the corner point 1292; for base unit30 this will be the laser light line 1238 that also will directlyintersect the corner point 1292.

Once both base units are directly aimed at corner point 1292, theazimuth angles are recorded at the remote unit 40 (see step 1512), andthis can be used to establish the second benchmark point. If desired,this can become the origin of the virtual floor plan, unless theprevious corner (the corner point 1282 from FIG. 36) was alreadyestablished as the origin.

Now that there are two benchmark points established with respect toknowing the azimuth angles for both base units, another piece ofinformation is desired, that being the actual distance between the twocorner points 1282 and 1292 (see step 1520). Once the actual distance isknown between the two new benchmarks (it might need to be accuratelymeasured), the virtual floor plan on the remote can be scaled to theactual dimensions of the room (see step 1522), and the virtual floorplan can become usable for laying out points of interest anywhere in theroom, and their actual distances and physical positions will be knownwith respect to the benchmarks. It will be understood that any one ofthe “legs” could be measured for an actual distance, to establish thetrue dimensions of the room with respect to the virtual floor plan. Forexample, the actual distance between the base unit 20 and the cornerpoint 1292 could be measured and the actual distance between either baseunit 20 and the other corner point 1282 could be measured; or the actualdistance between the other base unit 30 and corner point 1292 could bemeasured. Once a set of these measurements is determined, the otherdimensions in the room can be established, based on the azimuth anglesinformation.

Routine to Scan a Room and Find its Perimeter

Referring now to FIG. 38, a new methodology is disclosed for creating avirtual floor plan in a built-out space that exists, but for which thejobsite user has no blueprint and no virtual floor plan at the outset.FIG. 38 is from the user's perspective, again, and shows the user withina room having a ceiling at 1210, a floor surface at 1212, a left wall1214, a front wall 1216, and a right wall 1218. An enhanced capabilitybase unit, generally designated by the reference numeral 1020, is placedon the floor surface 1212 (see step 1530 of the flow chart on FIG. 52),and it is put into an automatic mode where it begins scanning the raised(e.g., vertical) surfaces of the space, using its distance measuringdevice (DMD). This base unit 1020 includes the components that aredepicted on FIG. 25, including a distance measurer 1228. In a preferredmode of this technology, a base unit of the type depicted by referencenumeral 1100 as depicted in FIG. 27 is used for this base unit 1020 thatis illustrated in FIG. 38. In other words, a laser distance measuringdevice 1028 (or perhaps a different type of DMD) would be used for thescanning procedure.

It will be understood that the terms “wall”, “vertical surface”, and“raised surface” all have a similar meaning in the context of structuresthat are to be scanned, or otherwise “measured” or “located” when usingthe equipment or methodologies of the technology disclosed herein. Theterm “space” often refers to a room, however, that room may not have aroof or ceiling—especially if the room is still under construction.Also, that room may not have four total walls; in other words, it mighthave only three walls and a large open area where a wall may some day beconstructed, or perhaps that open area may remain open forever, and inthat situation the room (or “space”) will not be totally enclosed. Thewalls to be scanned, measured, or located may not truly be verticalacross their entire surface, or they may not be “full” structures thatextend all the way from a floor surface to a ceiling surface—yet theyare nevertheless going to be referred herein to as “walls.” All that isrequired to be a “wall” for use with the technology disclosed herein, isthat the “wall” be a substantially flat structure, and that it extendaway from the floor surface (typically in a vertical direction). Formost applications, the “wall” will need to be a structure that can bereadily discerned by the user; otherwise the “wall” will have theappearance of a mere “bump,” and not be very useful for any purpose. Ofcourse, even a “bump” could be somehow enhanced, such as with visualindicia, such as a reflector, or reflective tape, or an activeelectronic device that outputs a signal when it receives energy, such aslaser light beams.

After the user 45 instructs the base unit 1020 to begin its automaticprocedure, the distance measuring device (DMD) begins rotating through ahorizontal plane, and records distances and azimuth angles at multiplelocations in a rotational direction along this horizontal plane (seestep 1532). On FIG. 38, these multiple scans are generally illustratedby the reference numeral 1300, which shows a separate laser light beamat multiple angular increments along the walls of the room, at theheight of the laser distance measuring device, with the base unit 1020resting on the floor surface 1212. During the scan, two of the laserlight lines will impact the two corners of the room (in this view), andthese two laser light lines are designated by the reference numerals1302 and 1304. The distance measuring device will be able to determinewhere the corners are (i.e., at the laser light lines 1302 and 1304),because the measured distance to and from those corners will be greaterthan the previous and subsequent distances measured by the DMD deviceduring the angular rotation of the laser distance measurer (see step1534). All this information will be automatically communicated to theremote unit 40 and a virtual floor plan of the room will begin to beconstructed on that remote unit, and this can be displayed, if desired.

At the end of the scanning procedure, in which the distance measuringdevice can be rotated through the entire 360 degrees of the horizontalplane within the area of the room, the corners will all be identified byboth their distances and their azimuth angles, with respect to thelocation of the base unit 1020. The user 45 will, of course, have to becognizant of his or her location in the room as this procedure is takingplace, and will need to stay out of the way of the laser light beamsbeing emitted by the distance measuring device during this procedure.

Once all of the azimuth angles and distances are accumulated into theremote unit 40, the entire room should be virtually constructed,including all the walls and all the corners. The exact location of thecorners might need to be inferred from data points that are very nearthe corners, but not absolutely in the precise location of the corners,depending upon the resolution of all of these measurements. The physicalcorners themselves may not be perfectly straight or sharp, and this alsocan be a reason that the corner locations might need to be inferred fromthis data. All the azimuth angles and distances are to be loaded intothe monitor 40, and its software program will be used to create thevirtual floor plan (see step 1536).

The goal is to establish two benchmark positions based upon thisinformation. In one sense, this procedure is much like the procedurediscussed above in reference to FIGS. 36 and 37, except there will be noneed for any “manual” aiming of the base units when using the moresophisticated base unit 1020 (which has its built-in distance measuringdevice). In this manner, the system described on FIG. 38 can be used toautomatically establish two benchmarks without any manual aiming of thefan beam of the laser transmitter 22 on that base unit.

As an option, the base unit 1020 can be slewed to one of the corners,and its fan beam laser transmitter can be turned on at that time. Thiswill allow the user to perform a visual inspection to verify theaccuracy from aiming of the laser distance meter (the DMD), and this canbe performed for all the corners, if desired. This optional turning onof the fan beam could occur during the automatic scanning procedure, asthe distance measuring device is slewing through its 360 degree transit,or after the initial virtual floor plan has been established on themonitor (the remote unit 40). The base unit could be commanded to aim atany one of the corners, then commanded to turn on its fan beam, and sothe user can perform the visual inspection to verify the accuracy of theaiming at that time.

A second base unit 1030 with similar enhanced capabilities as base unit1020 is placed on the floor 1212 (see step 1540). Once it is placed inthe room it could optionally perform its own automatic scanningprocedure using the distance measuring device; or it could be used tocreate an alignment axis with the first base unit 1020, as per themethodologies discussed above. Once the alignment axis has been created,and along with the virtual floor plan that has been created by the firstbase unit 1020, then benchmarks can be easily created (see step 1542),and other points of interest can then be scanned and located. The entireroom can be scaled and laid-out as desired (see step 1544).

Routine to Square Vertical Plane Up to a Wall

Referring now to FIG. 39, a user 45 is again standing in a built-outspace, which has a ceiling surface 1210, a floor surface 1212, a leftwall 1214, a front wall 1216, and a right wall 1218. The user will useone of the base units with enhanced capabilities, generally designatedby the reference numeral 1020, which has a distance measuring devicemounted near its top (see step 1550 on the flow chart of FIG. 53). Thisis the same type of base unit that is illustrated on FIGS. 25 and 27,and in a preferred mode of the technology disclosed herein, the distancemeasuring device will be a laser distance meter, such as the device 1028illustrated on FIG. 27. In this configuration, the laser distancemeasuring device will emit a light beam 1194 along the same plane as thefan beam 178 that is emitted from the same rotating platform 152.

Using the remote unit 40 as a command and monitoring device, the userwill instruct the base unit 1020 to scan along the wall 1218 using thelaser distance meter, which is illustrated on FIG. 39 by example laserlight lines 1310, 1312, and 1314. The fan beam can also be turned on,which will emit an upper edge line at 1322, a lower edge line at 1324,which will produce lines along the ceiling at 1326 and along the floorat 1328. As its rotatable platform 152 turns, the base unit 1020 willemit laser light lines at multiple angular positions; the laser lightline 1312 is perpendicular to the wall surface 1218. The laser lightlines produced by the laser distance meter will be several inches abovethe floor surface, depending on the height of the base unit 1020.

Referring now to FIG. 40, it can be seen that the laser light line 1310is at an angle 1357 with respect to the assumed perpendicular line 1312,and the laser line 1314 is also at an angle 1358 with respect to thatassumed perpendicular line 1312.

When the base unit 1020 begins scanning the wall surface 1218, it is notknown exactly which of the laser light lines will be the perpendicularline, so the rotating platform on the base unit will scan both left andright, which on FIG. 40 is counterclockwise, then clockwise (as lookingfrom above), so that most of the wall surface 1218 will be scanned bythe distance measuring device (see step 1552).

As the laser distance meter determines the actual physical distancebetween the base unit 1220 and the various points along the wall surface1218, the corresponding azimuth angle will also be recorded at eachscanning position, and all of this information can be stored on theremote unit 40, after it is transmitted from the base unit 1020. Theazimuth angle that corresponds to the shortest distance found by thelaser distance meter will be the line 1312, and that will become theperpendicular line of importance. The point along the wall surface 1218where laser light line 1312 intersects the wall surface is designated atthe reference numeral 1352.

Since the angular displacement seen from above (see FIG. 40) will tendto vary quite a bit near the perpendicular point 1352 while the actualdifference in distance between the base unit 1020 and the wall surface1218 varies only a small amount, the user 45 may have some troubledetermining which exact angular position belongs to the perpendicularline 1312. This will be related to the sine function, while attemptingto measure the change in slope of the sine curve as the angle equals ornears zero degrees. As is well known, the derivative of a sine curve isthe cosine function, which has a value near zero when its angleapproaches zero degrees. Therefore, the use of the present technologycan be enhanced by using a preferred methodology, described in theparagraph immediately below.

Another way to determine the correct angular position of theperpendicular line can be automated, or the user can manually create aninitial angle to get the procedure started. As indicated by the arcuatearrows on FIG. 40, the base unit 1020 can be slewed to the line 1310,and the distance can be taken at that point between the base unit andthe wall surface 1218 (at the point 1354). The base unit can then beslewed in the clockwise direction (as seen from above in FIG. 40) to theposition along the line 1314, and the distance can be measured betweenthe base unit and the wall surface (i.e., at the point 1356). Theazimuth angles will be recorded at both of these measurement locations.The angle between the perpendicular line 1312 and the line 1310 isdesignated angle 1357. The angle between the perpendicular line 1312 andthe other line 1314 is designated angle 1358.

The preferred procedure is to manually control the value for the angle1357 so that it causes the light line 1310 to be aimed quite a distanceaway from the point 1352, but so it still impacts the side wall 1218,and does not go past the corner (which would cause the distancemeasuring device to aim at the wall surface 1216). The distance of line1310 is now measured by the DMD. Then, either under automatic or manualcontrol, cause the base unit 1020 to slew in the clockwise direction sothat it aims at the point where the angle 1358 is the same angular valueas was the angle 1357. The distance of line 1314 will now be measured.If, by chance, the distance of the line segment 1314 is precisely equalto the distance of the line segment 1310, then the correct angularposition of the perpendicular line 1312 will exactly bi-sect thecombined values of the angles 1357 plus 1358. Almost assuredly this willnever actually occur (at least, not to any appreciable accuracy).

Once the distance 1314 is known, as compared to the distance 1310, thenthe base unit 1020 can be commanded to slew either left or right untilit finds a distance along the line 1314 that exactly matches thedistance 1310 (at least to within the accuracy of the laser distancemeasuring device). Once that position is found, then the correct valueof the angle 1358 will become known, and the additive values of theangles 1357 plus 1358 will allow the base unit 1020 to move to aposition that exactly bi-sects the two lines 1310 and 1314 (see step1554). That angular position will be the correct azimuth angle of thebase unit, and once it has been slewed to that angular position, it willbe aimed at a substantially perpendicular spot on the wall 1218, whichis the point 1352. That will determine the correct perpendicular line1312.

Once the exact spot of 1352 has been determined, the fan beam can beturned on, which will create a vertical line 1350 along the wall 1218(see FIG. 39) and the bottom of that vertical line 1350 will intersectthe floor 1212, and there will also be a horizontal visible laser lightline 1328 that runs right to that intersection point (see step 1560).This will be a horizontal 90 degree corner between the wall 1218 and thefloor 1212. That point can be used as a position for a chalk line alongthe perpendicular line 1312, between the point 1352 and the base unitposition. The user can now easily create that chalk line (see step1562), and this is very useful, particularly over long distances(several feet or several meters). Once that chalk line has been created,the same procedure with the same equipment can be used to draw severalother parallel chalk lines along that same wall (see step 1564).Alternatively, other parallel chalk lines can be created by offsettingfrom this initial line, at several locations along line 1312, includinglocations quite some distance away from the wall 1218. If this is alarge room, the length of the line 1312 could be over 100 feet, forexample, and it would be a simple matter to exactly measure an end pointaway from the wall 1218 that is parallel to the chalk line 1312, tocreate one or more parallel chalk lines on that same floor surface 1212.The alternative approach is to use the base unit 1020 at a differentlocation in the room along the wall 1218, and the same proceduredescribed above can be used to create other perpendicular lines withrespect to the wall surface 1218.

Another possible use of the base unit 1020 is to position it at a pointon the floor surface 1212 and to aim the fan beam directly at a pointanywhere on one of the wall surfaces. This point could be a non-surveyedpoint but it would be a point of interest to the user. For example, ifthe user had already located a position along the wall surface 1218 formounting an electrical outlet near the floor (such as near where it says“90 degrees” along the wall surface 1218 on FIG. 39), that user might beinterested in placing a wall switch a few feet above that same point. Byaiming the fan beam directly at the outlet (near where it says 90degrees on FIG. 39), a vertical line of laser light will then appear onthe wall surface at 1350. The user could then measure up the wall acertain distance to locate the switch plate. This, of course is only oneexample, and the user would be able to locate anything along thatvertical line 1350 all the way up to the ceiling; this acts as a plumbline with respect to the initial point of interest.

Routine to Create Benchmarks Along a Wall

Referring now to FIG. 41, the enhanced capability base units 1020 and1030 are positioned at locations on the floor surface 1212. Amethodology will now be described (see step 1570 on the flow chart ofFIG. 54) for setting up each transmitter of the base units to create asingle line on a wall, and then taking a distance measurement from eachtransmitter with its laser distance measurer device. The initialconditions for this methodology are an existing space on a jobsite, butthe user 45 has no blueprint, and also has no virtual floor plan on theremote unit 40. The two base units are used to create an alignment axistherebetween, which is the axis 1340, using one of the methodologiesdiscussed above (see step 1572).

Once the alignment axis 1340 has been established, the two base units1020 and 1030 are both controlled to aim at the same point (or line) onthe wall surface 1216. This is done by turning on the fan beams for bothlaser transmitters of the base units 1020 and 1030, so that they bothaim at the same point on the floor, at 1362 (see step 1574). There willbe a fan beam upper edge 1322 and fan beam lower edge 1324 emitted fromthe base unit 1020, and these fan beams will run across the ceiling as alaser light line at 1326 and across the floor as a laser light line at1328. This fan beam will then create a vertical line 1360 that is plumb,and vertically above the point on the floor 1362.

Laser transmitter 30 will also create a fan beam upper edge 1332 and fanbeam lower edge 1334, which will create fan beam laser light lines alongthe ceiling at 1336 and along the floor at 1338. This fan beam will alsocreate the same vertical line 1360 after correct aiming, which willintersect the point on the floor at 1362.

The point 1362 will be a point of interest for the user 45. Once bothfan beams from the base units 1020 and 1030 are aimed at the correctpoint 1362, then the azimuth angles of both base units will be recordedon the remote unit (see step 1576). In addition, the distance measuringdevice will be used to determine the exact distance along a laser lightline 1306 (assuming the DMD of base unit 1020 is a laser distancemeter); the base unit 1030 will also be able to measure a precisedistance using its DMD along a laser light line 1308 (assuming the DMDof base unit 1030 is a laser distance meter). Laser light line 1306 willbe a few inches above the fan beam floor line 1328, and the laser lightline 1308 will be a few inches above the fan beam floor line 1338. Allthese laser light lines will intersect along the vertical plumb line1360. At least one of the distances of the lines 1306 and 1308 will berecorded on the remote unit 40 (see step 1578).

The point 1362 can now become a benchmark point on the virtual floorplan that will be created in the remote unit 40 (see step 1580). Thispoint could be assigned the coordinates 0,0 and thereby become theorigin point for this virtual floor plan. Alternatively it could beassigned a different coordinate value later.

The alignment axis information can now be used to scale the field ofwork. The distance between the two base units 1020 and 1030 is needed(which can be calculated as described above from establishing thealignment axis, or it can be directly measured by one of the laserdistance meters), the distance between one of the base units and thepoint of interest is needed (i.e., the distance along the line 1306 orthe line 1308), and the above azimuth angle information is needed. Afterthese variables are known, the other variables in the geometry of thetriangle that is created by the lines 1340, 1306, and 1308 can besolved, and all the angles and distances of this triangle become known.Therefore, if the distance 1306 is measured, then the distance 1308 canbe calculated, and the field of work can be scaled (see step 1582); or,if the distance 1308 is measured, then the distance 1306 can becalculated, and again, the field of work can be scaled.

Once the distances and angular positions have been recorded for thepoint 1362, with respect to both base units 1020 and 1030, then both ofthose base units can have their fan beams aimed at another point in theroom (see step 1584). For example, they could both be aimed at thecorner to the right (at seen on FIG. 41), and the intersection of thatcorner with the floor is a point 1364. Both fan beams could be aimed sothat their fan beam floor lines 1328 and 1338 intersect right at thecorner point 1364. This will establish a new location at which theazimuth angles can be measured and recorded on the remote unit 40 (seestep 1586). The distance measuring devices can then be actuated and atleast one of the laser light line distances 1306 and 1308 (now aimed atthe corner above the point 1364) can be determined, and at least one ofthose distances then is recorded on the remote unit 40 (see step 1588).These measurements can now be used to create a second virtual benchmarkat the point 1364 (see step 1590). This point could be assigned as theorigin of the floor plan, if desired.

Since the distances of the lines 1306 and 1308 are now known withrespect to both benchmark points 1362 and 1364, the distances from thosepoints to each base unit 1020 and 1030 can be calculated, and thedistance along the alignment axis 1340 can also be determined (see step1572). With the coordinates of both benchmarks 1362 and 1364 now known,with respect to the alignment axis 1340, the entire field of work cannow be oriented to the alignment axis. This will make it easier for theuser to lay out additional points of interest in that field of work. Anyother point in that space can now be laid out, and put into the virtualfloor plan of the remote unit 40, and after appropriate scaling, allsuch points will have actual distances assigned thereto.

In an alternative mode of using this technology, the two base units canbe provided with distance measuring devices, but only one of the baseunits uses an azimuth angle encoder. The initial point of interest isagain at 1362 on FIG. 41, and both fan beams from the base units 1020and 1030 are aimed at point 1362. The azimuth angle of only one of thebase units 1020 or 1030 will be recorded on the remote unit (as analternative step 1576). The distance measuring device can be used todetermine the exact distance along a laser light line 1306 (assuming theDMD of base unit 1020 is a laser distance meter); and base unit 1030will also be able to measure a precise distance using its DMD along alaser light line 1308 (assuming the DMD of base unit 1030 is a laserdistance meter). Laser light line 1306 will be a few inches above thefan beam floor line 1328, and the laser light line 1308 will be a fewinches above the fan beam floor line 1338. All these laser light lineswill intersect along the vertical plumb line 1360. Both of the distancesof the lines 1306 and 1308 will be recorded on the remote unit 40 (seestep 1578).

The point 1362 can now become a benchmark point on the virtual floorplan that will be created in the remote unit 40 (see step 1580), and thealignment axis information can now be used to scale the field of work.The distance between the two base units 1020 and 1030 is needed, thedistance between both of the base units and the point of interest isneeded (i.e., the distance along the line 1306 and the line 1308), andthe above azimuth angle information is needed. After these variables areknown, the other variables in the geometry of the triangle that iscreated by the lines 1340, 1306, and 1308 can be solved, and all theangles and distances of this triangle become known. Therefore, the fieldof work can be scaled (see step 1582).

As before, once the distances and angular positions have been recordedfor the point 1362, with respect to both base units 1020 and 1030, thenboth of those base units can have their fan beams aimed at another point(e.g., point 1364) in the room (see step 1584). This will establish anew location at which one of the azimuth angles can be measured andrecorded on the remote unit 40 (see step 1586). The distance measuringdevices can then be actuated and both of the laser light line distances1306 and 1308 can be determined and recorded on the remote unit 40 (seestep 1588). These measurements can now be used to create a secondvirtual benchmark at the point 1364 (see step 1590).

As before, the distances of the lines 1306 and 1308 are now known withrespect to both benchmark points 1362 and 1364, and the distance alongthe alignment axis 1340 can be determined (see step 1572). Thecoordinates of both benchmarks 1362 and 1364 are now known with respectto the alignment axis 1340, and the entire field of work can now beoriented to the alignment axis. Any other point in that space can now belaid out, and put into the virtual floor plan of the remote unit 40, andafter appropriate scaling, all such points will have actual distancesassigned thereto.

Active Target

Another piece of hardware will now be described, in reference to FIG.42. A new device referred to herein as an “active target”, generallydesignated by the reference numeral 1400, will include some of thehardware components that are found in a remote unit 40. For example,there will be a microprocessor 1410, with associated random accessmemory 1412 and read only memory 1414. There will be some input/outputinterfacing circuitry at 1418, and an address/data bus at 1415, whichcarries information between the microprocessor and these other devices.The I/O circuitry 1418 will be in communication with a communicationsport 1402, which includes some type of transmitter 1403 thatcommunicates with a first base unit 20 and second base unit 30, alongcommunication links 1405. In general, the communication links 1405 willbe wireless pathways, so that the active target 1400 does not need to bephysically connected to any other devices.

There also is a type of “start” switch 1419 that is in communicationwith the I/O circuitry 1418. In a preferred mode of the technologydisclosed herein, the start switch will merely be an on-off switch, andthe active target will be a fully automatic device that will run throughits executable programming automatically once it has been activated. Inan alternative embodiment, the active target could be previouslyenergized, but “resting” in a low power and low-activity state, until itis awakened when laser light strikes it; it could then run through itsexecutable programming automatically.

The active target 1400 will also include an omni-directional sensor 1408that can receive, and be sensitive to, laser light that impacts thesensor from any direction along a 360 degree horizontal plane. Oneexample of such a sensor will be a rod sensor similar to the sensor 230as depicted on FIG. 3. This would be a rod sensor with only a singlephotocell, such as described above. The output of this sensor would bedirected to a gain stage 1407, and the output of that gain stage isdirected to a demodulation circuit 1406. The output from thedemodulation circuit is directed to the I/O circuitry 1418, so that themicroprocessor can essentially be in communication with theomni-directional sensor 1408.

It is desired that the omni-directional sensor be designed with acertain required accuracy with regard to determining its centeringposition of reception of the laser light beam. The gain stage 1407 andthe modulation circuit 1406 may need to be exceptionally high insensitivity, because omni-directional sensors have a tendency to bequite lossy. An automatic gain control (AGC) circuit may be needed, forgain stage 1407.

Routine Using an Active Target

Referring now to FIG. 43, a methodology for use of the active target1400 will now be described. Starting with a user 45 having a remote unit40 in a space, it will be assumed that there is no virtual floor plan inthe remote unit 40 (see step 1600 on the flow chart of FIG. 55). Thereare two base units 20 and 30, and they have established an alignmentaxis 1440 therebetween, as according to one of the methodologiesdiscussed above (see step 1602). There are no benchmarks as of yet, andthe active target will be used for that purpose.

The active target 1400 can be placed at any point on the floor surface1212; this can be any particular point of interest to the user, and thispoint can become a benchmark, if desired. In fact, that is one of themore useful purposes of using the active target.

Referring now to FIG. 44, the active target is activated (see step1604), and this occurs by the user approaching the active target deviceand pressing the “start” switch (which can be an on-off switch, asdescribed above; or, in an alternative embodiment as before, the activetarget could be previously energized, but “resting” in a low power andlow-activity state, until it is awakened when laser light strikes it).The active target 1400 will now send commands to the two base units 20and 30, probably through the remote unit 40. This is a preferred mode,although the active target could also be programmed to communicatedirectly with the two base units, if desired. However, on manyconstruction sites, the remote unit 40 will be an IP master, and it willhave its own website address that can be found and communicated with bythe active target. This has some advantages that should be considered inthe system design.

It should be noted that, for this particular methodology, the base units20 and 30 are not required to be enhanced performance units with adistance measuring device. Of course, such enhanced performance unitscan be used, but the distance measurement device capabilities are notrequired for this methodology.

Referring now to FIG. 45, the active target is now controlling themovements of the rotating platform of the base unit 20. The laser fanbeam has been turned on, and its upper edge line 1422 creates one ormore laser light lines on the ceiling, and its lower fan beam edge 1424creates laser light lines along the floor surface 1212. The activetarget commands the platform to slew in the counterclockwise direction(as seen from above) so that the first fan beam laser line on the flooris at 1425, a later position places the fan beam laser light at 1426,and a yet later position places the fan beam laser light line at 1427.These lines are moved in the angular direction 1428 (as seen on FIG. 45)due to the rotational slewing motion. When the fan beam is aimed alongthe laser light line 1427, it intersects the omni-directionalphotosensor of the active target 1400, and the active target will send acommand instructing the base unit 20 to stop its motion (see step 1610).The fan beam will now remain at that position 1427. The active targetcan also send additional messages commanding the rotating platform ofthe base unit 20 to slew back and forth until the laser light line 1427is impacting the center portion of the omni-directional photocell, for aprecise alignment.

Referring now to FIG. 46, the active target 1400 now commands the otherbase unit 30 to undergo the same procedure. The fan beam is turned onand its upper limit edge 1432 will impact the ceiling, while its lowerlimit will create laser light lines along the floor. Such laser lightlines will change position as the active target commands the base unit30 to rotate its platform so that the fan beam moves along the floor, inthe direction of the arrow 1438. So an initial position of the laserlight line along the floor would be at 1435, and then as the angleadvances a later laser light line would be at 1436, and a yet laterlaser light line would be at 1437. Once the fan beam reaches theposition where it produces the laser light line at 1437, it impacts theomni-directional photosensor of the active target 1400, and the activetarget will now send a command telling the base unit 30 to ceaserotating its fan beam (see step 1612).

The active target 1400 can now send further instructions to command thebase unit 30 to slew its fan beam back and forth until the laser lightline 1437 becomes centered on the omni-directional photosensor for aprecise alignment. Once the laser fan beams of both base units 20 and 30are aligned with the omni-directional photosensor of the active target,a situation has been created that is illustrated in FIG. 47. The two fanbeams are now crossing at the active target, and this creates a verticalplumb line 1442 directly above the active target location. This willappear on the floor surface as an “X” shaped set of laser light lines ifthe active target is removed. This will establish a benchmark point, ifdesired. If a physical benchmark point was already seen on the floorsurface 1212, then the active target will now become that benchmarkpoint on a virtual floor plan stored in the remote unit 40 (see step1614). Since the alignment axis 1440 has been established between thetwo base units 20 and 30, this first benchmark point is now availableinformation along the intersecting lines 1442. Once that information isknown, the active target can be moved to another position to create asecond benchmark point (see steps 1620 and 1622). If there is a physicalbenchmark point visible to the user, then the active target can be movedto that point, and by going through the same procedure as describedabove in reference to FIGS. 44-46, then that second benchmark point willautomatically become known to the virtual floor plan stored in theremote unit 40. In addition, there will be a crossing of the laser lightlines 1427 and 1437 at that second benchmark position, once the activetarget is removed. Once all of this information has been established,the entire room or space can be scaled, and any points of interest onthe room can be surveyed and/or laid out (see step 1624).

It will be understood that a second active target could be used on thesame floor surface, and in fact it could be placed at a second benchmarkposition while the first active target has been placed at the firstbenchmark position. In a preferred mode of operation, the second activetarget would not be activated until the first active target was doneestablishing its position with the two base units. It will also be notedthat the fan beams of the base units will probably be modulated laserlight, so that they can be easily differentiated from ambient light atthe omni-directional photosensor of the active target. It might also behelpful for the two base units to each use a different modulatingfrequency for their respective fan beams. Finally, if both activetargets are to be activated simultaneously, then there would need to bea different form of communication by each active target, either withdifferent encoding, or different communications modulation frequencies,for example.

Routine Using Fixed-Length Rod

Referring now to FIG. 48, a rod of fixed length is placed on the floorsurface (see step 1634 on the flow chart of FIG. 56), as depicted inthis view. The rod is designated by the reference numeral 1450, and isplaced at a location some distance away from the two base units 20 and30 (see step 1630). An alignment axis 1440 has already been established(see step 1632) before this procedure continues. As an initialcondition, there is no virtual floor plan in the remote unit 40; orperhaps there is a virtual floor plan available, but it is not yetloaded with any benchmarks.

Referring now to FIG. 49, the two base units have their fan beams aimedat (or proximal to) one end of the rod, at a point 1452 (see step 1640).Base unit 20 emits a fan beam with an upper laser limit edge 1462 thatcreates a upper ceiling line 1466; it also emits a lower laser limitedge 1464, which creates a laser floor line 1468 that intersects the endpoint 1452 of the rod. Base unit 30 also has its fan beam turned onwhich emits an upper limit fan beam edge 1472 and a lower limit fan beamedge 1474. These create a ceiling laser line 1476 and a floor laser line1478, and this last line intersects the point 1452. Once thisintersection point is established by the two fan beams, that point canbecome a benchmark, if desired. The recorded azimuth angles and theestablished alignment axis will allow that point to be entered into avirtual floor plan on the remote unit 40 (see step 1642). At this time,the floor plan is not scaled.

Referring now to FIG. 50, the two fan beams of the base units are nowdirected at (or proximal to) the opposite end of the fixed rod, at apoint 1454 (see step 1650). Once that point has been intersected by thetwo fan beams, the azimuth angles of the base units can be recorded, andthe floor plan on the remote unit 40 will receive that information (seestep 1652). Since the rod 1450 is of a known length, the room can now bescaled, and all points of the virtual floor plan can be related to atrue physical distance and axis transformation can take place (see step1654).

The fixed rod 1450 can be physically constructed in a great many numbersof ways. The surface of the rod preferably will have some type ofindicia thereon to provide two precise locations on the rod that are tobe used for the intersection points 1452 and 1454. Such indicia can beof four general categories: (1) a marking directly on the rod's surface,(2) a protrusion on the rod's surface, presumably one that extendsupward to make its appearance more visible, (3) an indentation (such asa notch) in the rod's surface, or (4) a fixture that can be used to holdan active target—in other words, active targets could be affixed to oneor both ends of the rod. The indicia can be located directly at the twoends of the rod (e.g., along the rod's longitudinal axis), or theindicia can be located very near the two ends; in either case, the twoindicia locations are deemed to be proximal to the two ends of the rod.And in all cases the distance between the two indicia points will be the“known actual length” that is of importance in establishing the true(actual, or physical) sizes of the jobsite for the virtual floor plan.

It will be understood that, for all of the systems described above, thelaser fan beams represent a static laser system. In other words, thelaser light itself is not moving along the vertical plane, but insteadis at a static position. Moreover, even if a rotating laser line or beamis used instead of a pure fan beam, or if a dithering laser line or beamis used (instead of a fan beam), this still represents a static system,because the overall effect of those dithering/rotating laser beams is asingle plane of laser light that is fixed in place, and it makes nodifference exactly where the laser beam is aimed at a given instant intime, because they all sweep quickly enough that it will make nodifference to the user. It will also make no difference to the equipmentbeing used to create the alignment axis or the benchmark axes, or thepoints of interest axes. This is quite different than certainconventional systems known in the prior art, in which the laser beamssweep through various angles, and tend to intercept each other only atcertain points in time to establish certain positional relationships,but only during certain moments. Those are the opposite of “static”pieces of equipment.

It will be understood that some of the logical operations described inrelation to the flow charts of FIGS. 5-7 and FIGS. 51-56 can beimplemented in electronic equipment using sequential logic (such as byusing microprocessor technology), or using a logic state machine, orperhaps by discrete logic; it even could be implemented using parallelprocessors. One preferred embodiment may use a microprocessor ormicrocontroller (e.g., one of the microprocessor 110, 210, or 310) toexecute software instructions that are stored in memory cells within anASIC. In fact, the one entire microprocessor (or a microcontroller, forthat matter), along with RAM and executable ROM, may be contained withina single ASIC, in one mode of the technology disclosed herein. Ofcourse, other types of circuitry could be used to implement theselogical operations depicted in the drawings without departing from theprinciples of the technology disclosed herein. In any event, some typeof processing circuit will be provided, whether it is based on amicroprocessor, a logic state machine, by using discrete logic elementsto accomplish these tasks, or perhaps by a type of computation devicenot yet invented; moreover, some type of memory circuit will beprovided, whether it is based on typical RAM chips, EEROM chips(including Flash memory), by using discrete logic elements to store dataand other operating information (such as the point coordinates datastored, for example, in memory elements 312 or 316), or perhaps by atype of memory device not yet invented.

It will also be understood that the precise logical operations depictedin the flow charts of FIGS. 5-7 and FIGS. 51-56, and discussed above,could be somewhat modified to perform similar, although not exact,functions without departing from the principles of the technologydisclosed herein. The exact nature of some of the decision steps andother commands in these flow charts are directed toward specific futuremodels of laser transmitter and receiver systems, and floor layoutportable computers (those involving Trimble Navigation laser and floorlayout equipment, for example) and certainly similar, but somewhatdifferent, steps would be taken for use with other models or brands oflaser equipment and floor layout computer systems in many instances,with the overall inventive results being the same.

With regard to process or method steps that are described herein, itwill be understood that the order in which some of the steps occur isnot always important or critical to correct interpretation of thetechnology disclosed herein. This is true with respect to some of themethod steps that are recited in the appended claims. For example, inthe flow chart on FIG. 55, step 1602 (establishing an alignment axisbetween the two base units) can occur before the active target is placedon the floor of the jobsite, which is part of the previous step 1600 onthat flow chart. As another example, after base unit “A” has been aimedat the active target in step 1610, a portion of the step 1614 could beperformed (i.e., recording the azimuth angle for base unit “A”) beforethe step 1612 occurs, which aims base unit “B” at the active target.While it is true that the method steps must proceed in a logical order,there is more than one possible logical order in many of themethodologies for the technology disclosed herein—i.e., there can be“parallel” logical flows in some cases. What is important is that thenecessary steps all occur in one of the possible logical orders.

As used herein, the term “proximal” can have a meaning of closelypositioning one physical object with a second physical object, such thatthe two objects are perhaps adjacent to one another, although it is notnecessarily required that there be no third object positionedtherebetween. In the technology disclosed herein, there may be instancesin which a “male locating structure” is to be positioned “proximal” to a“female locating structure.” In general, this could mean that the twomale and female structures are to be physically abutting one another, orthis could mean that they are “mated” to one another by way of aparticular size and shape that essentially keeps one structure orientedin a predetermined direction and at an X-Y (e.g., horizontal andvertical) position with respect to one another, regardless as to whetherthe two male and female structures actually touch one another along acontinuous surface. Or, two structures of any size and shape (whethermale, female, or otherwise in shape) may be located somewhat near oneanother, regardless if they physically abut one another or not; or avertical wall structure could be positioned at or near a specific pointon a horizontal floor or ceiling surface; such a relationship could betermed “proximal.” Or, two or more possible locations for a particularpoint can be specified in relation to a precise attribute of a physicalobject, such as being “near” or “at” the end of a stick; all of thosepossible near/at locations could be deemed “proximal” to the end of thatstick. Moreover, the term “proximal” can also have a meaning thatrelates strictly to a single object, in which the single object may havetwo ends, and the “distal end” is the end that is positioned somewhatfarther away from a subject point (or area) of reference, and the“proximal end” is the other end, which would be positioned somewhatcloser to that same subject point (or area) of reference.

All documents cited in the Background and in the Detailed Descriptionare, in relevant part, incorporated herein by reference; the citation ofany document is not to be construed as an admission that it is prior artwith respect to the technology disclosed herein.

The foregoing description of a preferred embodiment has been presentedfor purposes of illustration and description. It is not intended to beexhaustive or to limit the technology disclosed herein to the preciseform disclosed, and the technology disclosed herein may be furthermodified within the spirit and scope of this disclosure. Any examplesdescribed or illustrated herein are intended as non-limiting examples,and many modifications or variations of the examples, or of thepreferred embodiment(s), are possible in light of the above teachings,without departing from the spirit and scope of the technology disclosedherein. The embodiment(s) was chosen and described in order toillustrate the principles of the technology disclosed herein and itspractical application to thereby enable one of ordinary skill in the artto utilize the technology disclosed herein in various embodiments andwith various modifications as are suited to particular usescontemplated. This application is therefore intended to cover anyvariations, uses, or adaptations of the technology disclosed hereinusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this technology disclosedherein pertains and which fall within the limits of the appended claims.

What is claimed is:
 1. A method for setting up a layout and pointtransfer system, said method comprising: (a) providing a first lasercontroller which includes a first processing circuit, a firstcommunications circuit, a first azimuth angle measuring instrument, arotatable first laser light transmitter that emits a first laser lightplane, and a rotatable first distance measuring meter that measuresdistance to a target; (b) providing a second laser controller whichincludes a second processing circuit, a second communications circuit, asecond azimuth angle measuring instrument, and a rotatable second laserlight transmitter that emits a second laser light plane; (c) providing aremote controller that includes a third processing circuit, a thirdcommunications circuit, a memory circuit including instructionsexecutable by said third processing circuit, a display, and an inputsensing circuit that allows a user to enter commands to said remotecontroller, said remote controller being in communication with saidfirst and second laser controllers; (d) positioning said first lasercontroller and said second laser controller at two different locationson a solid surface of a jobsite; (e) determining an alignment axisbetween said first laser controller and said second laser controller;(f) starting a new virtual jobsite floor plan in said memory circuit ofthe remote controller, for a field of work at said jobsite; (g)selecting a first physical point on said solid surface of the jobsiteand aiming said first laser light transmitter and said second laserlight transmitter so that said first physical point is indicated by bothlaser light lines that are produced by said first and second laser lightplanes; (h) determining a first set of azimuth angles of said first andsecond laser light transmitters; (i) determining a first distancebetween said first physical point and said first distance measuringmeter; (j) recording said first set of azimuth angles and first distancein said memory circuit of the remote controller, thereby creating afirst benchmark for said virtual floor plan stored in said memorycircuit; (k) calculating a second distance between said first and secondlaser controllers, thereby scaling the field of work; and (l) after saidfield of work has been scaled, using both said first and second lasercontrollers to determine coordinates of for at least one point ofinterest at said jobsite, without using said rotatable first distancemeasuring meter.
 2. The system of claim 1, wherein: said first andsecond laser controllers are configured to provide a visualrepresentation of a virtual point on said physical jobsite surface, byaiming said first laser light plane and said second laser light plane,to indicate a physical location of said virtual point.
 3. The system ofclaim 2, wherein: (a) said first laser light plane creates a firstvisual laser light line along said physical jobsite surface; (b) saidsecond laser light plane creates a second visual laser light line alongsaid physical jobsite surface; and (c) said visual representationcomprises said first and second visual laser light lines intersecting atsaid virtual point.
 4. The system of claim 1, wherein said first andsecond planes of laser light comprise at least one of: (a) a staticlaser fan beam; (b) a rotating laser light beam; and (c) a ditheringlaser light beam.
 5. The method of claim 1, wherein: (a) said firstazimuth angle measuring instrument comprises at least one of: (i) afirst azimuth position encoder, and (ii) a first visual angle scale; and(b) said second azimuth angle measuring instrument comprises at leastone of: (i) a second azimuth position encoder, and (ii) a second visualangle scale.
 6. The method of claim 1, wherein: (a) said first lasercontroller includes: (i) a first leveling platform; (ii) a first azimuthposition encoder; and (iii) a first azimuth motor drive forautomatically positioning said first laser light transmitter, undercontrol of said remote controller; and (b) said second laser controllerincludes: (i) a second leveling platform; (ii) a second azimuth positionencoder; and (iii) a second azimuth motor drive for automaticallypositioning said second laser light transmitter, under control of saidremote controller.
 7. A method for setting up a layout and pointtransfer system, said method comprising: (a) providing a first lasercontroller which includes a first processing circuit, a firstcommunications circuit, a first azimuth angle measuring instrument, arotatable first laser light transmitter that emits a first laser lightplane, and a rotatable first distance measuring meter that measuresdistance to a target; (b) providing a second laser controller whichincludes a second processing circuit, a second communications circuit, arotatable second laser light transmitter that emits a second laser lightplane, and a rotatable second distance measuring meter that measuresdistance to a target; (c) providing a remote controller that includes athird processing circuit, a third communications circuit, a memorycircuit including instructions executable by said third processingcircuit, a display, and an input sensing circuit that allows a user toenter commands to said remote controller, said remote controller beingin communication with said first and second laser controllers; (d)positioning said first laser controller and said second laser controllerat two different locations on a solid surface of a jobsite; (e)determining an alignment axis between said first laser controller andsaid second laser controller; (f) starting a new virtual jobsite floorplan in said memory circuit of the remote controller, for a field ofwork at said jobsite; (g) selecting a first physical point on said solidsurface of the jobsite and aiming said first laser light transmitter andsaid second laser light transmitter so that said first physical point isindicated by both laser light lines that are produced by said first andsecond laser light planes; (h) determining a first azimuth angle of saidfirst laser light transmitter; (i) determining a first set of distancesbetween said first physical point and said first and second distancemeasuring meters; (j) recording said first azimuth angle and first setof distances in said memory circuit of the remote controller, therebycreating a first benchmark for said virtual floor plan stored in saidmemory circuit; (k) calculating a second distance between said first andsecond laser controllers, thereby scaling the field of work; and (l)after said field of work has been scaled, using both said first andsecond laser controllers to determine coordinates of for at least onepoint of interest at said jobsite, without using said rotatable firstdistance measuring meter.
 8. The system of claim 7, wherein said firstand second planes of laser light comprise at least one of: (a) a staticlaser fan beam; (b) a rotating laser light beam; and (c) a ditheringlaser light beam.
 9. The method of claim 7, wherein: (a) said firstazimuth angle measuring instrument comprises at least one of: (i) anazimuth position encoder; and (ii) a visual angle scale.
 10. The methodof claim 7, wherein: (a) said first laser controller includes: (i) afirst leveling platform; (ii) a first azimuth position encoder; and(iii) a first azimuth motor drive for automatically positioning saidfirst laser light transmitter, under control of said remote controller;and (b) said second laser controller includes: (i) a second levelingplatform.